[PATCH] initramfs: Fix spurious rebuilds

[Florian Fainelli]

Commit 35e669e1a254 ("initramfs: select builtin initram
compression algorithm on KConfig instead of Makefile") makes suffix_y be
a quote variable, which can be illustrated looking at the build output:

  GEN     usr/initramfs_data.cpio".gz"

Make sure that we do strip off double quotes from
CONFIG_INITRAMFS_COMPRESSION, since the Makefile tracks targets with
unquoted suffixes.

Fixes: 35e669e1a254 ("initramfs: select builtin initram compression algorithm on KConfig instead of Makefile")
Signed-off-by: Florian Fainelli <f.fainelli@xxxxxxxxx>
---
This is against v4.10-rc2, thanks!

 usr/Makefile | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/usr/Makefile b/usr/Makefile
index 17a513268325..a9ae8b493e2b 100644
--- a/usr/Makefile
+++ b/usr/Makefile
@@ -5,7 +5,7 @@
 klibcdirs:;
 PHONY += klibcdirs
 
-suffix_y = $(CONFIG_INITRAMFS_COMPRESSION)
+suffix_y = $(subst ",,$(CONFIG_INITRAMFS_COMPRESSION))
 AFLAGS_initramfs_data.o += -DINITRAMFS_IMAGE="usr/initramfs_data.cpio$(suffix_y)"
 
 # Generate builtin.o based on initramfs_data.o
-- 
2.9.3