[openwrt/openwrt] build: add --force option to gzip in Build/gzip

[LEDE Commits]

stintel pushed a commit to openwrt/openwrt.git, branch master:
https://git.lede-project.org/138c76332b7e39b3c4e3018e7792e74645ab0c7a

commit 138c76332b7e39b3c4e3018e7792e74645ab0c7a
Author: Stijn Tintel <stijn at linux-ipv6.be>
AuthorDate: Mon Feb 19 23:03:00 2018 +0100

    build: add --force option to gzip in Build/gzip
    
    When using pigz, a parallel gzip implementation, the gzip step in the
    image build for some targets fails, because the image filename already
    has the .gz extension. This results in an emtpy image file. Fix this by
    adding the --force option to gzip in the Build/gzip macro.
    
    Signed-off-by: Stijn Tintel <stijn at linux-ipv6.be>
    Tested-by: Martin Schleier <drahemmaps at gmx.net>
---
 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 555a9e5..9ec3a84 100644
--- a/include/image-commands.mk
+++ b/include/image-commands.mk
@@ -133,7 +133,7 @@ define Build/lzma-no-dict
 endef
 
 define Build/gzip
-	gzip -9n -c $@ $(1) > $@.new
+	gzip --force -9n -c $@ $(1) > $@.new
 	@mv $@.new $@
 endef