make depend should recurse into libswscale as well.

Originally committed as revision 6406 to svn://svn.ffmpeg.org/ffmpeg/trunk

Makefile

@@ -208,6 +208,9 @@ depend: .depend
 ifeq ($(CONFIG_PP),yes)
 	$(MAKE) -C libpostproc depend
 endif
+ifeq ($(CONFIG_SWSCALER),yes)
+	$(MAKE) -C libswscale  depend
+endif
 ifeq ($(BUILD_VHOOK),yes)
 	$(MAKE) -C vhook       depend
 endif