[PATCH] Makefile: Fix build with scan-build

[Amadeusz Sławiński]

When building kernel with scan-build for analysis:
$ scan-build make defconfig
$ scan-build make menuconfig # disable RETPOLINE
$ scan-build make -j16 bindeb-pkg
since commit 7d73c3e9c514 ("Makefile: remove stale cc-option checks")
it fails with:
  CC      scripts/mod/empty.o
could not find clang line
make[4]: *** [scripts/Makefile.build:287: scripts/mod/empty.o] Error 1

Seems like changes to how -fconserve-stack support was detected broke
build with scan-build. Revert part of mentioned commit which changed
that.

Fixes: 7d73c3e9c514 ("Makefile: remove stale cc-option checks")
CC: Nick Desaulniers <ndesaulniers@xxxxxxxxxx>
Signed-off-by: Amadeusz Sławiński <amadeuszx.slawinski@xxxxxxxxxxxxxxx>
Reviewed-by: Cezary Rojewski <cezary.rojewski@xxxxxxxxx>
---
 Makefile | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/Makefile b/Makefile
index 765115c99655..1174ccd182f5 100644
--- a/Makefile
+++ b/Makefile
@@ -991,9 +991,7 @@ KBUILD_CFLAGS	+= -fno-strict-overflow
 KBUILD_CFLAGS  += -fno-stack-check
 
 # conserve stack if available
-ifdef CONFIG_CC_IS_GCC
-KBUILD_CFLAGS   += -fconserve-stack
-endif
+KBUILD_CFLAGS   += $(call cc-option,-fconserve-stack)
 
 # Prohibit date/time macros, which would make the build non-deterministic
 KBUILD_CFLAGS   += -Werror=date-time
-- 
2.25.1