Quote directory name from cmake wrapper

Signed-off-by: Dave Rodgman <dave.rodgman@arm.com>
diff --git a/tests/scripts/quiet/cmake b/tests/scripts/quiet/cmake
index 10a0b25..3723473 100755
--- a/tests/scripts/quiet/cmake
+++ b/tests/scripts/quiet/cmake
@@ -15,4 +15,4 @@
 
 export TOOL="cmake"
 
-exec $(dirname "$0")/quiet "$@"
+exec "$(dirname "$0")/quiet" "$@"