Use clang-format-9 binary in Github Actions (#1088)

Signed-off-by: Ellen Norris-Thompson <ellen.norris-thompson@arm.com>
diff --git a/check-format.sh b/check-format.sh
index 7eae2fd..7de2bd2 100755
--- a/check-format.sh
+++ b/check-format.sh
@@ -2,12 +2,10 @@
 
 # Arg used to specify non-'origin/master' comparison branch
 ORIGIN_BRANCH=${1:-"origin/master"}
+CLANG_BINARY=${2:-"`which clang-format-9`"}
 
 # Run git-clang-format to check for violations
-if [ "$TRAVIS" == "true" ]; then
-    EXTRA_OPTS="--binary `which clang-format-9`"
-fi
-CLANG_FORMAT_OUTPUT=$(git-clang-format --diff $ORIGIN_BRANCH --extensions c,cpp,h,hpp $EXTRA_OPTS)
+CLANG_FORMAT_OUTPUT=$(git-clang-format --diff $ORIGIN_BRANCH --extensions c,cpp,h,hpp --binary $CLANG_BINARY)
 
 # Check for no-ops
 grep '^no modified files to format$' <<<"$CLANG_FORMAT_OUTPUT" && exit 0