Don't unnecessarily borrow dereferenced values explicitly

warning: this expression borrows a value the compiler would automatically borrow
  --> gstreamer-rtsp-server/src/rtsp_session_pool.rs:16:5
   |
16 |     (&mut *func.borrow_mut())(&from_glib_borrow(pool)).into_glib()
   |     ^^^^^^^^^^^^^^^^^^^^^^^^^ help: change this to: `(*func.borrow_mut())`
   |
   = note: `#[warn(clippy::needless_borrow)]` on by default
   = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_borrow

gstreamer-app/src/app_sink.rs

@@ -169,9 +169,7 @@ unsafe extern "C" fn trampoline_eos(appsink: *mut ffi::GstAppSink, callbacks: gp
     }
 
     if let Some(ref eos) = callbacks.eos {
-        let result = panic::catch_unwind(panic::AssertUnwindSafe(|| {
+        let result = panic::catch_unwind(panic::AssertUnwindSafe(|| (*eos.borrow_mut())(&element)));
-            (&mut *eos.borrow_mut())(&element)
-        }));
         match result {
             Ok(result) => result,
             Err(err) => {
@@ -197,7 +195,7 @@ unsafe extern "C" fn trampoline_new_preroll(
 
     let ret = if let Some(ref new_preroll) = callbacks.new_preroll {
         let result = panic::catch_unwind(panic::AssertUnwindSafe(|| {
-            (&mut *new_preroll.borrow_mut())(&element).into()
+            (*new_preroll.borrow_mut())(&element).into()
         }));
         match result {
             Ok(result) => result,
@@ -230,7 +228,7 @@ unsafe extern "C" fn trampoline_new_sample(
 
     let ret = if let Some(ref new_sample) = callbacks.new_sample {
         let result = panic::catch_unwind(panic::AssertUnwindSafe(|| {
-            (&mut *new_sample.borrow_mut())(&element).into()
+            (*new_sample.borrow_mut())(&element).into()
         }));
         match result {
             Ok(result) => result,
@@ -263,7 +261,7 @@ unsafe extern "C" fn trampoline_new_event(
 
     let ret = if let Some(ref new_event) = callbacks.new_event {
         let result = panic::catch_unwind(panic::AssertUnwindSafe(|| {
-            (&mut *new_event.borrow_mut())(&element)
+            (*new_event.borrow_mut())(&element)
         }));
         match result {
             Ok(result) => result,

gstreamer-app/src/app_src.rs

@@ -137,7 +137,7 @@ unsafe extern "C" fn trampoline_need_data(
 
     if let Some(ref need_data) = callbacks.need_data {
         let result = panic::catch_unwind(panic::AssertUnwindSafe(|| {
-            (&mut *need_data.borrow_mut())(&element, length)
+            (*need_data.borrow_mut())(&element, length)
         }));
         match result {
             Ok(result) => result,

gstreamer-rtsp-server/src/rtsp_session_pool.rs

@@ -13,7 +13,7 @@ unsafe extern "C" fn trampoline_watch<F: FnMut(&RTSPSessionPool) -> Continue + S
     func: gpointer,
 ) -> gboolean {
     let func: &RefCell<F> = &*(func as *const RefCell<F>);
-    (&mut *func.borrow_mut())(&from_glib_borrow(pool)).into_glib()
+    (*func.borrow_mut())(&from_glib_borrow(pool)).into_glib()
 }
 
 unsafe extern "C" fn destroy_closure_watch<

gstreamer/src/bus.rs

@@ -24,7 +24,7 @@ unsafe extern "C" fn trampoline_watch<F: FnMut(&Bus, &Message) -> Continue + Sen
     func: gpointer,
 ) -> gboolean {
     let func: &RefCell<F> = &*(func as *const RefCell<F>);
-    (&mut *func.borrow_mut())(&from_glib_borrow(bus), &Message::from_glib_borrow(msg)).into_glib()
+    (*func.borrow_mut())(&from_glib_borrow(bus), &Message::from_glib_borrow(msg)).into_glib()
 }
 
 unsafe extern "C" fn destroy_closure_watch<
@@ -48,7 +48,7 @@ unsafe extern "C" fn trampoline_watch_local<F: FnMut(&Bus, &Message) -> Continue
 ) -> gboolean {
     let func: &glib::thread_guard::ThreadGuard<RefCell<F>> =
         &*(func as *const glib::thread_guard::ThreadGuard<RefCell<F>>);
-    (&mut *func.get_ref().borrow_mut())(&from_glib_borrow(bus), &Message::from_glib_borrow(msg))
+    (*func.get_ref().borrow_mut())(&from_glib_borrow(bus), &Message::from_glib_borrow(msg))
         .into_glib()
 }
 

gstreamer/src/pad.rs

@@ -1598,7 +1598,7 @@ unsafe extern "C" fn destroy_closure<F>(ptr: gpointer) {
 
 unsafe extern "C" fn trampoline_pad_task<F: FnMut() + Send + 'static>(func: gpointer) {
     let func: &RefCell<F> = &*(func as *const RefCell<F>);
-    (&mut *func.borrow_mut())()
+    (*func.borrow_mut())()
 }
 
 fn into_raw_pad_task<F: FnMut() + Send + 'static>(func: F) -> gpointer {