suppressed redundant math.h - suppressed M_PI redefinition

Originally committed as revision 1419 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavcodec/ratecontrol.c

@@ -17,8 +17,6 @@
  * License along with this library; if not, write to the Free Software
  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  */
-#include <math.h>
-#include "common.h"
 #include "avcodec.h"
 #include "dsputil.h"
 #include "mpegvideo.h"
@@ -26,10 +24,6 @@
 #undef NDEBUG // allways check asserts, the speed effect is far too small to disable them
 #include <assert.h>
 
-#ifndef M_PI
-#define M_PI 3.14159265358979323846
-#endif
-
 #ifndef M_E
 #define M_E 2.718281828
 #endif