[source] build: make NETGEAR_REGION optional in netgear-chk

[LEDE Commits]

mkresin pushed a commit to source.git, branch master:
https://git.lede-project.org/2c2fc50d06cf18f7f5120a201e101aaa42f070c1

commit 2c2fc50d06cf18f7f5120a201e101aaa42f070c1
Author: Joseph C. Lehner <joseph.c.lehner at gmail.com>
AuthorDate: Fri Mar 3 15:37:01 2017 +0100

    build: make NETGEAR_REGION optional in netgear-chk
    
    This patch makes specifying NETGEAR_REGION optional, in which case
    mkchkimage will default to region 1 (WW).
    
    Signed-off-by: Joseph C. Lehner <joseph.c.lehner at gmail.com>
---
 include/image-commands.mk | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/include/image-commands.mk b/include/image-commands.mk
index c513f19..c1d8982 100644
--- a/include/image-commands.mk
+++ b/include/image-commands.mk
@@ -49,7 +49,7 @@ define Build/netgear-chk
 		-o $@.new \
 		-k $@ \
 		-b $(NETGEAR_BOARD_ID) \
-		-r $(NETGEAR_REGION)
+		$(if $(NETGEAR_REGION),-r $(NETGEAR_REGION),)
 	mv $@.new $@
 endef