gcc.h: change "mpd_" prefix to "gcc_"

This is specific to gcc, not to mpd.

src/gcc.h

@@ -27,28 +27,28 @@
  */
 
 #if defined(__GNUC__) && (__GNUC__ >= 3)
-#  define mpd_must_check	__attribute__ ((warn_unused_result))
-#  define mpd_packed		__attribute__ ((packed))
+#  define gcc_must_check	__attribute__ ((warn_unused_result))
+#  define gcc_packed		__attribute__ ((packed))
 /* these are very useful for type checking */
-#  define mpd_printf		__attribute__ ((format(printf,1,2)))
-#  define mpd_fprintf		__attribute__ ((format(printf,2,3)))
-#  define mpd_fprintf_		__attribute__ ((format(printf,3,4)))
-#  define mpd_fprintf__		__attribute__ ((format(printf,4,5)))
-#  define mpd_scanf		__attribute__ ((format(scanf,1,2)))
-#  define mpd_used		__attribute__ ((used))
+#  define gcc_printf		__attribute__ ((format(printf,1,2)))
+#  define gcc_fprintf		__attribute__ ((format(printf,2,3)))
+#  define gcc_fprintf_		__attribute__ ((format(printf,3,4)))
+#  define gcc_fprintf__		__attribute__ ((format(printf,4,5)))
+#  define gcc_scanf		__attribute__ ((format(scanf,1,2)))
+#  define gcc_used		__attribute__ ((used))
 /* #  define inline	inline __attribute__ ((always_inline)) */
-#  define mpd_noinline		__attribute__ ((noinline))
+#  define gcc_noinline		__attribute__ ((noinline))
 #else
-#  define mpd_must_check
-#  define mpd_packed
-#  define mpd_printf
-#  define mpd_fprintf
-#  define mpd_fprintf_
-#  define mpd_fprintf__
-#  define mpd_scanf
-#  define mpd_used
+#  define gcc_must_check
+#  define gcc_packed
+#  define gcc_printf
+#  define gcc_fprintf
+#  define gcc_fprintf_
+#  define gcc_fprintf__
+#  define gcc_scanf
+#  define gcc_used
 /* #  define inline */
-#  define mpd_noinline
+#  define gcc_noinline
 #endif
 
 #endif /* MPD_GCC_H */

src/tag.h

@@ -73,7 +73,7 @@ struct tag_item {
 	 * the value of this tag; this is a variable length string
 	 */
 	char value[sizeof(long)];
-} mpd_packed;
+} gcc_packed;
 
 /**
  * The meta information about a song file.  It is a MPD specific