[PATCH] kernel: prevent unnecessary rebuilding due to config_data.gz

[Peter Foley <pefoley2@verizon.net>]

When IKCONFIG is built-in make oldconfig will cause the kernel to be 
relinked even if .config didn't change. This happens because of a 
config_data.gz dependency on .config. This patch changes the if_changed to 
a filechk so that config_data.h is only rebuilt when the contents 
have actually changed.

Signed-off-by: Peter Foley <pefoley2@verizon.net>
---
 kernel/Makefile |    5 ++---
 1 files changed, 2 insertions(+), 3 deletions(-)

diff --git a/kernel/Makefile b/kernel/Makefile
index 2d64cfc..d06467f 100644
--- a/kernel/Makefile
+++ b/kernel/Makefile
@@ -125,11 +125,10 @@ targets += config_data.gz
 $(obj)/config_data.gz: $(KCONFIG_CONFIG) FORCE
 	$(call if_changed,gzip)
 
-quiet_cmd_ikconfiggz = IKCFG   $@
-      cmd_ikconfiggz = (echo "static const char kernel_config_data[] __used = MAGIC_START"; cat $< | scripts/bin2c; echo "MAGIC_END;") > $@
+      filechk_ikconfiggz = (echo "static const char kernel_config_data[] __used = MAGIC_START"; cat $< | scripts/bin2c; echo "MAGIC_END;")
 targets += config_data.h
 $(obj)/config_data.h: $(obj)/config_data.gz FORCE
-	$(call if_changed,ikconfiggz)
+	$(call filechk,ikconfiggz)
 
 $(obj)/time.o: $(obj)/timeconst.h
 
-- 
1.7.5.3