[PATCH] x86: fix build with older gcc

[Jan Beulich]

Older gcc (observed with 4.1.x) doesn't support -Wno-override-init and
also doesn't ignore unknown -Wno-* options.

Fixes: 5e44258d16 "x86/build: Reduce the W=1 warnings noise when compiling x86 syscall tables"
Signed-off-by: Jan Beulich <jbeulich@xxxxxxxx>
Cc: Valdis Kletnieks <valdis.kletnieks@xxxxxx> 
---
 arch/x86/entry/Makefile |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

--- 4.9-rc2/arch/x86/entry/Makefile
+++ 4.9-rc2-x86-entry-build/arch/x86/entry/Makefile
@@ -5,8 +5,8 @@
 OBJECT_FILES_NON_STANDARD_entry_$(BITS).o   := y
 OBJECT_FILES_NON_STANDARD_entry_64_compat.o := y
 
-CFLAGS_syscall_64.o		+= -Wno-override-init
-CFLAGS_syscall_32.o		+= -Wno-override-init
+CFLAGS_syscall_64.o		+= $(call cc-option,-Wno-override-init,)
+CFLAGS_syscall_32.o		+= $(call cc-option,-Wno-override-init,)
 obj-y				:= entry_$(BITS).o thunk_$(BITS).o syscall_$(BITS).o
 obj-y				+= common.o