Fix a few more miscellaneous (harmless) Clang warnings.

headers/os/media/MediaDefs.h

@@ -18,7 +18,7 @@
 #endif
 
 
-struct media_node;
+class media_node;
 
 #define B_MEDIA_NAME_LENGTH 64
 
@@ -401,7 +401,7 @@ struct media_video_header {
 	uint32      display_line_width; // Number of pixels per display_line
 	uint32      display_line_count;	// Sum of all interlace fields lines
 	uint32      bytes_per_row;		// Number of bytes in a display_line
-									// (padding bytes excluded)	
+									// (padding bytes excluded)
 	uint16      pixel_width_aspect;	// 1:1 has 1 here, 4:3 has 4 here
 									// 16:9 has 16 here!
 	uint16      pixel_height_aspect;// 1:1 has 1 here, 4:3 has 3 here

src/add-ons/kernel/file_systems/bfs/BPlusTree.h

@@ -361,7 +361,7 @@ private:
 private:
 			friend class TreeIterator;
 			friend class CachedNode;
-			friend class TreeCheck;
+			friend struct TreeCheck;
 
 			Inode*				fStream;
 			bplustree_header	fHeader;

src/add-ons/media/plugins/ffmpeg/AVCodecDecoder.cpp

@@ -81,10 +81,11 @@ struct avformat_codec_context {
 
 // profiling related globals
 #define DO_PROFILING 0
-
+#if DO_PROFILING
 static bigtime_t decodingTime = 0;
 static bigtime_t conversionTime = 0;
 static long profileCounter = 0;
+#endif
 
 
 AVCodecDecoder::AVCodecDecoder()
@@ -1616,7 +1617,7 @@ AVCodecDecoder::_UpdateMediaHeaderForVideoFrame()
 	for correct operation
 
 	You should only call this function when you	got a new picture decoded by
-	the video decoder. 
+	the video decoder.
 
 	When this function finishes the postprocessed video frame will be available
 	in fPostProcessedDecodedPicture and fDecodedData (fDecodedDataSizeInBytes