ARM: 8945/1: decompressor: use CONFIG option instead of cc-option

The Kconfig stage (arch/Kconfig) has already evaluated whether the
compiler supports -fno-stack-protector.

You can use CONFIG_CC_HAS_STACKPROTECTOR_NONE instead of invoking
the compiler to check the flag here.
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>

arch/arm/boot/compressed/Makefile

@@ -110,12 +110,12 @@ endif
 
 # -fstack-protector-strong triggers protection checks in this code,
 # but it is being used too early to link to meaningful stack_chk logic.
-nossp_flags := $(call cc-option, -fno-stack-protector)
-CFLAGS_atags_to_fdt.o := $(nossp_flags)
-CFLAGS_fdt.o := $(nossp_flags)
-CFLAGS_fdt_ro.o := $(nossp_flags)
-CFLAGS_fdt_rw.o := $(nossp_flags)
-CFLAGS_fdt_wip.o := $(nossp_flags)
+nossp-flags-$(CONFIG_CC_HAS_STACKPROTECTOR_NONE) := -fno-stack-protector
+CFLAGS_atags_to_fdt.o := $(nossp-flags-y)
+CFLAGS_fdt.o := $(nossp-flags-y)
+CFLAGS_fdt_ro.o := $(nossp-flags-y)
+CFLAGS_fdt_rw.o := $(nossp-flags-y)
+CFLAGS_fdt_wip.o := $(nossp-flags-y)
 
 ccflags-y := -fpic $(call cc-option,-mno-single-pic-base,) -fno-builtin -I$(obj)
 asflags-y := -DZIMAGE