deps-libff: Skip further decode refresh if aborted

Skip decode refresh scheduling if the abort flag is
set when the timer fails to start.  This avoids extraneous
refresh scheduling when tearing down the decoders.

deps/libff/libff/ff-decoder.c

@@ -205,6 +205,12 @@ void ff_decoder_refresh(void *opaque)
 				// Our clock was never started and deleted or
 				// aborted
 
+				if (decoder->refresh_timer.abort) {
+					av_log(NULL, AV_LOG_INFO,
+						"refresh timer aborted");
+					return;
+				}
+
 				// Drop this frame? The only way this can happen
 				// is if one stream finishes before another and
 				// the input is looping or canceled.  Until we