fs/squashfs: fix image file permissions

Set image file permissions to 0644 like it was before the fs rework,
instead of the rather unhelpful 0700 (E.G. when image is used for tftp).

Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk>

fs/squashfs/squashfs.mk

@@ -19,7 +19,8 @@ endif
 
 define ROOTFS_SQUASHFS_CMD
 	$(HOST_DIR)/usr/bin/mksquashfs $(TARGET_DIR) $$@ -noappend \
-		$(ROOTFS_SQUASHFS_ARGS)
+		$(ROOTFS_SQUASHFS_ARGS) && \
+	chmod 0644 $$@
 endef
 
 $(eval $(call ROOTFS_TARGET,squashfs))