csound: Fix nightly compiler warning in test

warning: trailing semicolon in macro used in expression position
   --> audio/csound/tests/csound_filter.rs:52:10
    |
52  |         );
    |          ^
...
403 |         &CSD!(ksmps, ichannels, ochannels, "ain, ain2 ins", "out ain"),
    |          ------------------------------------------------------------- in this macro invocation
    |
    = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
    = note: for more information, see issue #79813 <https://github.com/rust-lang/rust/issues/79813>
    = note: this warning originates in the macro `CSD` (in Nightly builds, run with -Z macro-backtrace for more info)

audio/csound/tests/csound_filter.rs

@@ -49,7 +49,7 @@ macro_rules! CSD {
             </CsScore>
             </CsoundSynthesizer>",
             $ksmps, $ichannels, $ochannels, $ins, $out
-        );
+        )
     };
 }