'#elseif' needs to be '#elif' patch by ("Steven M. Schultz": sms, 2BSD COM)

Originally committed as revision 4510 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavformat/grab_bktr.c

@@ -30,7 +30,7 @@
 #  include <machine/ioctl_meteor.h>
 #  include <machine/ioctl_bt848.h>
 # endif
-#elseif defined(__DragonFly__)
+#elif defined(__DragonFly__)
 # include <dev/video/meteor/ioctl_meteor.h>
 # include <dev/video/bktr/ioctl_bt848.h>
 #else