rtsp: Vertically align a constant definition

Signed-off-by: Martin Storsjö <martin@martin.st>

libavformat/rtsp.h

@@ -390,7 +390,7 @@ typedef struct RTSPState {
 #define RTSP_FLAG_FILTER_SRC  0x1    /**< Filter incoming UDP packets -
                                           receive packets only from the right
                                           source address and port. */
-#define RTSP_FLAG_LISTEN 0x2         /**< Wait for incoming connections. */
+#define RTSP_FLAG_LISTEN      0x2    /**< Wait for incoming connections. */
 
 /**
  * Describe a single stream, as identified by a single m= line block in the