kbuild: remove cc-option test of -fno-stack-check

The minimal compiler version, GCC 4.9 supports this flag.

Nathan Chancellor pointed out:
 "This flag is technically ignored by clang (see commit
 05b0798916f01690b5903302e51f3136274e291f) but that obviously
 does not matter for the sake of this."

Here is the godbolt:
https://godbolt.org/z/59cK6o

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nathan Chancellor <natechancellor@gmail.com>
diff --git a/Makefile b/Makefile
index 7036dcb..3722b42 100644
--- a/Makefile
+++ b/Makefile
@@ -940,7 +940,7 @@
 KBUILD_CFLAGS	+= $(call cc-option,-fmerge-constants)
 
 # Make sure -fstack-check isn't enabled (like gentoo apparently did)
-KBUILD_CFLAGS  += $(call cc-option,-fno-stack-check,)
+KBUILD_CFLAGS  += -fno-stack-check
 
 # conserve stack if available
 KBUILD_CFLAGS   += $(call cc-option,-fconserve-stack)