Typo and grammar fix

git-svn-id: file:///var/local/repositories/ffmpeg/trunk@14177 9553f0bf-9b14-0410-a0b8-cfaf0461ba5b

libavcodec/acelp_filters.h

@@ -90,7 +90,7 @@ extern const int16_t ff_acelp_interp_filter[61];
  *
  * filter_coeffs contains coefficients of the positive half of the symmetric
  * interpolation filter. filter_coeffs[0] should the central (unpaired) coefficient.
- * See ff_acelp_interp_filter fot example.
+ * See ff_acelp_interp_filter for an example.
  *
  */
 void ff_acelp_interpolate(