From fba168f5745acac95db519a9984b62e3e508df6a Mon Sep 17 00:00:00 2001
From: Mathew McBride <matt@traverse.com.au>
Date: Wed, 28 Mar 2018 13:34:52 +1100
Subject: [PATCH] build: use busybox gzip compatible force option

commit 138c763 ("build: add --force option to gzip in Build/gzip")
added the --force flag to the gzip invocation.

Under environments with busybox gzip (e.g Alpine Linux), this fails
as busybox only recognizes "-f".

Signed-off-by: Mathew McBride <matt@traverse.com.au>
---
 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 a848655399..e0322080e9 100644
--- a/include/image-commands.mk
+++ b/include/image-commands.mk
@@ -135,7 +135,7 @@ define Build/lzma-no-dict
 endef
 
 define Build/gzip
-	gzip --force -9n -c $@ $(1) > $@.new
+	gzip -f -9n -c $@ $(1) > $@.new
 	@mv $@.new $@
 endef