gstreamer: Make switch passthrough as such

vasnprintf requires special handling since the following 'case' is #ifdef'ed

Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/8229>

subprojects/gstreamer/gst/printf/vasnprintf.c

@@ -646,7 +646,7 @@ vasnprintf (char *resultbuf, size_t *lengthp, const char *format, va_list args)
               break;
 #else
               *p++ = 'l';
-               /*FALLTHROUGH*/
+              G_GNUC_FALLTHROUGH;
 #endif
 #endif
             case TYPE_LONGINT:

subprojects/gstreamer/plugins/elements/gstfakesrc.c

@@ -617,6 +617,7 @@ gst_fake_src_prepare_buffer (GstFakeSrc * src, guint8 * data, gsize size)
     }
     case FAKE_SRC_FILLTYPE_PATTERN:
       src->pattern_byte = 0x00;
+      /* FALLTHROUGH */
     case FAKE_SRC_FILLTYPE_PATTERN_CONT:
     {
       gint i;

subprojects/gstreamer/plugins/elements/gstoutputselector.c

@@ -640,8 +640,8 @@ gst_output_selector_event (GstPad * pad, GstObject * parent, GstEvent * event)
       gst_event_copy_segment (event, &sel->segment);
       GST_DEBUG_OBJECT (sel, "configured SEGMENT %" GST_SEGMENT_FORMAT,
           &sel->segment);
-      /* fall through */
     }
+      /* FALLTHROUGH */
     default:
     {
       active = gst_output_selector_get_active (sel);

subprojects/gstreamer/plugins/elements/gstqueue2.c

@@ -2671,8 +2671,8 @@ gst_queue2_handle_sink_event (GstPad * pad, GstObject * parent,
           g_object_notify_by_pspec (G_OBJECT (queue), obj_props[PROP_BITRATE]);
         }
       }
-      /* Fall-through */
     }
+      /* FALLTHROUGH */
     default:
       if (GST_EVENT_IS_SERIALIZED (event)) {
         gboolean bitrate_changed = TRUE;

subprojects/gstreamer/plugins/elements/gsttypefindelement.c

@@ -720,8 +720,8 @@ gst_type_find_element_sink_event (GstPad * pad, GstObject * parent,
           typefind->cached_events = NULL;
           gst_adapter_clear (typefind->adapter);
           GST_OBJECT_UNLOCK (typefind);
-          /* fall through */
         }
+          /* FALLTHROUGH */
         case GST_EVENT_FLUSH_START:
           res = gst_pad_push_event (typefind->src, event);
           break;

subprojects/gstreamer/tests/check/gst/gstpad.c

@@ -340,6 +340,7 @@ sink_query_caps (GstPad * pad, GstObject * object, GstQuery * q)
           " query-only-field=(int)1");
       gst_query_set_caps_result (q, caps);
       gst_caps_unref (caps);
+      /* FALLTHROUGH */
     default:
       ret = gst_pad_query_default (pad, object, q);
       break;

subprojects/gstreamer/tests/check/gst/gstutils.c

@@ -1621,6 +1621,7 @@ testpadreqsink_peer_query (GstPad * pad, GstObject * parent, GstQuery * query)
         res = TRUE;
         break;
       }
+      /* FALLTHROUGH */
     default:
       res = gst_pad_query_default (pad, parent, query);
       break;