Add missing comment markers to #endif directive.

Originally committed as revision 9455 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavformat/nut.h

@@ -99,4 +99,4 @@ static unsigned long av_crc04C11DB7_update(unsigned long checksum, const uint8_t
     return av_crc(av_crc04C11DB7, checksum, buf, len);
 }
 
-#endif AVFORMAT_NUT_H
+#endif /* AVFORMAT_NUT_H */