selftests/x86: Add validity check and allow field splitting

stable inclusion
from stable-v5.10.110
commit 8265bea7d8cd9006649dee961f9a1cd3949b726c
bugzilla: https://gitee.com/openeuler/kernel/issues/I574AL

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=8265bea7d8cd9006649dee961f9a1cd3949b726c

--------------------------------

[ Upstream commit b06e15eb ]

Add check to test if CC has a string. CC can have multiple sub-strings
like "ccache gcc". Erorr pops up if it is treated as single string and
double quotes are used around it. This can be fixed by removing the
quotes and not treating CC as a single string.

Fixes: e9886ace ("selftests, x86: Rework x86 target architecture detection")
Reported-by: N"kernelci.org bot" <bot@kernelci.org>
Signed-off-by: NMuhammad Usama Anjum <usama.anjum@collabora.com>
Signed-off-by: NDave Hansen <dave.hansen@linux.intel.com>
Link: https://lkml.kernel.org/r/20220214184109.3739179-2-usama.anjum@collabora.comSigned-off-by: NSasha Levin <sashal@kernel.org>
Signed-off-by: NYu Liao <liaoyu15@huawei.com>
Reviewed-by: NWei Li <liwei391@huawei.com>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>

tools/testing/selftests/x86/check_cc.sh

@@ -7,7 +7,7 @@ CC="$1"
 TESTPROG="$2"
 shift 2
 
-if "$CC" -o /dev/null "$TESTPROG" -O0 "$@" 2>/dev/null; then
+if [ -n "$CC" ] && $CC -o /dev/null "$TESTPROG" -O0 "$@" 2>/dev/null; then
     echo 1
 else
     echo 0