kbuild: dummy-tools: adjust to scripts/cc-version.sh

Commit aec6c60 ("kbuild: check the minimum compiler version in
Kconfig") changed how the script detects the compiler version.

Get 'make CROSS_COMPILE=scripts/dummy-tools/' back working again.

Fixes: aec6c60 ("kbuild: check the minimum compiler version in Kconfig")
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Tested-by: Nathan Chancellor <nathan@kernel.org>
Acked-by: Miguel Ojeda <ojeda@kernel.org>

scripts/dummy-tools/gcc

@@ -57,9 +57,9 @@ if arg_contain --version "$@"; then
 fi
 
 if arg_contain -E "$@"; then
-	# For scripts/gcc-version.sh; This emulates GCC 20.0.0
+	# For scripts/cc-version.sh; This emulates GCC 20.0.0
 	if arg_contain - "$@"; then
-		sed 's/^__GNUC__$/20/; s/^__GNUC_MINOR__$/0/; s/^__GNUC_PATCHLEVEL__$/0/'
+		sed -n '/^GCC/{s/__GNUC__/20/; s/__GNUC_MINOR__/0/; s/__GNUC_PATCHLEVEL__/0/; p;}'
 		exit 0
 	else
 		echo "no input files" >&2