add missing include of bswap.h

git-svn-id: file:///var/local/repositories/ffmpeg/trunk@8853 9553f0bf-9b14-0410-a0b8-cfaf0461ba5b

libavutil/sha1.c

@@ -3,6 +3,7 @@
 // based on public domain SHA-1 code by Steve Reid <steve@edmweb.com>
 
 #include "common.h"
+#include "bswap.h"
 #include "sha1.h"
 
 typedef struct AVSHA1 {