floorf() is not used, and causes warnings on Solaris

Originally committed as revision 5617 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavutil/common.h

@@ -182,12 +182,6 @@ typedef uint64_t      uint_fast64_t;
 #    endif
 #endif
 
-#if defined(CONFIG_OS2) || defined(CONFIG_SUNOS)
-static inline float floorf(float f) {
-    return floor(f);
-}
-#endif
-
 #ifdef CONFIG_WIN32
 
 /* windows */