Add missing strings.h include needed for strcasecmp.

git-svn-id: file:///var/local/repositories/ffmpeg/trunk@19920 9553f0bf-9b14-0410-a0b8-cfaf0461ba5b

libavdevice/bktr.c

@@ -44,6 +44,7 @@
 #include <sys/mman.h>
 #include <sys/time.h>
 #include <signal.h>
+#include <strings.h>
 
 typedef struct {
     int video_fd;