remove [U]INT64_C definition

Originally committed as revision 8127 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavutil/common.h

@@ -63,11 +63,6 @@
 #endif
 #endif
 
-#ifndef INT64_C
-#define INT64_C(c)     (c ## LL)
-#define UINT64_C(c)    (c ## ULL)
-#endif
-
 //rounded divison & shift
 #define RSHIFT(a,b) ((a) > 0 ? ((a) + ((1<<(b))>>1))>>(b) : ((a) + ((1<<(b))>>1)-1)>>(b))
 /* assume b>0 */