MT#55283 fix AMR tests mem leaks

... reported by asan

Change-Id: I36d909af873362160b0e914686b8ff15d381c156

t/test-amr-decode.c

@@ -43,6 +43,7 @@ static int frame_cb(decoder_t *dec, AVFrame *frame, void *u1, void *u2) {
 		}
 	}
 	args->done = true;
+	av_frame_free(&frame);
 	return 0;
 }
 

t/test-amr-encode.c

@@ -93,6 +93,7 @@ static void do_test_amr_xx(const char *file, int line,
 
 	encoder_free(e);
 	free(fmtp_buf);
+	av_frame_free(&frame);
 
 	printf("test ok: %s:%i\n", file, line);
 }

t/test-transcode.c

@@ -123,6 +123,7 @@ static void codec_set(char *c) {
 			break;
 		splitter.len = cp - splitter.s;
 	}
+	free(c);
 }
 #endif