Add multiple inclusion guards.

Originally committed as revision 12255 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavcodec/faanidct.h

@@ -19,6 +19,11 @@
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  */
 
+#ifndef FFMPEG_FAANIDCT_H
+#define FFMPEG_FAANIDCT_H
+
 void ff_faanidct(DCTELEM block[64]);
 void ff_faanidct_add(uint8_t *dest, int line_size, DCTELEM block[64]);
 void ff_faanidct_put(uint8_t *dest, int line_size, DCTELEM block[64]);
+
+#endif /* FFMPEG_FAANIDCT_H */