libsvgtiny: fix clean command name

Thanks to Thomas for noticing.

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

package/libsvgtiny/libsvgtiny.mk

@@ -45,7 +45,7 @@ define LIBSVGTINY_UNINSTALL_TARGET_CMDS
 		$(MAKE) -C $(@D) PREFIX=/usr DESTDIR=$(TARGET_DIR) uninstall
 endef
 
-define BZIP2_CLEAN_CMDS
+define LIBSVGTINY_CLEAN_CMDS
 	$(TARGET_CONFIGURE_ENV) $(TARGET_CONFIGURE_OPTS) \
 		$(MAKE) -C $(@D) clean
 endef