UPSTREAM: kbuild: use CONFIG_CC_VERSION_TEXT to construct LINUX_COMPILER macro

scripts/mkcompile_h runs $(CC) just for getting the version string.
Reuse CONFIG_CC_VERSION_TEXT for optimization.

For GCC, this slightly changes the version string. I do not think it
is a big deal as we do not have the defined format for LINUX_COMPILER.
In fact, the recent commit 4831f7ad6c569 ("kbuild: mkcompile_h:
Include $LD version in /proc/version") added the linker version.

Bug: 168274246

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
(cherry picked from commit 9a950154668729a472d17b8e307d92e7c60f45f7)
Signed-off-by: Mars Lin <marslin@google.com>
Change-Id: I66bac5b44bf764e7c0e432ae17bcdf06d79c96d0

init/Makefile

@@ -33,4 +33,4 @@ include/generated/compile.h: FORCE
 	@$($(quiet)chk_compile.h)
 	$(Q)$(CONFIG_SHELL) $(srctree)/scripts/mkcompile_h $@	\
 	"$(UTS_MACHINE)" "$(CONFIG_SMP)" "$(CONFIG_PREEMPT)"	\
-	"$(CC)" "$(LD)"
+	$(CONFIG_CC_VERSION_TEXT) "$(LD)"

scripts/mkcompile_h

@@ -5,7 +5,7 @@ TARGET=$1
 ARCH=$2
 SMP=$3
 PREEMPT=$4
-CC=$5
+CC_VERSION="$5"
 LD=$6
 
 vecho() { [ "${quiet}" = "silent_" ] || echo "$@" ; }
@@ -73,7 +73,6 @@ UTS_TRUNCATE="cut -b -$UTS_LEN"
   echo \#define LINUX_COMPILE_BY \"`echo $LINUX_COMPILE_BY | $UTS_TRUNCATE`\"
   echo \#define LINUX_COMPILE_HOST \"`echo $LINUX_COMPILE_HOST | $UTS_TRUNCATE`\"
 
-  CC_VERSION=$($CC -v 2>&1 | grep ' version ' | sed 's/[[:space:]]*$//')
   LD_VERSION=$($LD -v | head -n1 | sed 's/(compatible with [^)]*)//' \
 		      | sed 's/[[:space:]]*$//')
   printf '#define LINUX_COMPILER "%s"\n' "$CC_VERSION, $LD_VERSION"