Globally rename the header inclusion guard names.

Consistently apply this rule: the guard name is obtained from the
filename by stripping the leading "lib", converting '/' and '.'  to
'_' and uppercasing the resulting name. Guard names in the root
directory have to be prefixed by "FFMPEG_".

Originally committed as revision 15120 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavcodec/alpha/asm.h

@@ -19,8 +19,8 @@
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  */
 
-#ifndef FFMPEG_ASM_H
-#define FFMPEG_ASM_H
+#ifndef AVCODEC_ALPHA_ASM_H
+#define AVCODEC_ALPHA_ASM_H
 
 #include <inttypes.h>
 
@@ -188,4 +188,4 @@ struct unaligned_long { uint64_t l; } __attribute__((packed));
 #error "Unknown compiler!"
 #endif
 
-#endif /* FFMPEG_ASM_H */
+#endif /* AVCODEC_ALPHA_ASM_H */