_ci-mac-homebrew.sh: fix to not install llvm for default native mac builds [ci skip]

Author: vszakats

_ci-mac-homebrew.sh

@@ -8,7 +8,7 @@ set -o xtrace -o errexit -o nounset; [ -n "${BASH:-}${ZSH_NAME:-}" ] && set -o p
 
 extra=''
 [[ "${CW_CONFIG:-}" = *'boringssl'* ]] && extra+=' go'
-if [[ "${CW_CONFIG:-}" != *'mac'* ]] || [[ "${CW_CONFIG:-}" != *'gcc'* ]]; then
+if [[ "${CW_CONFIG:-}" != *'mac'* ]] || [[ "${CW_CONFIG:-}" = *'llvm'* ]]; then
   extra+=' llvm lld'
 fi