Build iptables using a single process

package/iptables/iptables.mk

@@ -25,7 +25,7 @@ $(IPTABLES_BUILD_DIR)/.configured: $(IPTABLES_BUILD_DIR)/.unpacked
 	touch $@
 
 $(IPTABLES_BUILD_DIR)/iptables: $(IPTABLES_BUILD_DIR)/.configured
-	$(MAKE) $(TARGET_CONFIGURE_OPTS) -C $(IPTABLES_BUILD_DIR) \
+	$(MAKE1) $(TARGET_CONFIGURE_OPTS) -C $(IPTABLES_BUILD_DIR) \
 		KERNEL_DIR=$(LINUX_HEADERS_DIR) \
 		COPT_FLAGS="$(TARGET_CFLAGS)" \
 		PREFIX=/usr \