double quote directory test condition

There are cases where result_loc value is empty and if not
double-quoted it, test is true, which is not the desired behavior

Signed-off-by: Leonardo Sandoval <leonardo.sandoval@linaro.org>
Change-Id: Ief484733b7ed5b13557535be2e7a8b4370726db0
diff --git a/script/scan_build_wrapper.sh b/script/scan_build_wrapper.sh
index ea359a2..af2d71f 100644
--- a/script/scan_build_wrapper.sh
+++ b/script/scan_build_wrapper.sh
@@ -37,7 +37,7 @@
 			| awk 'BEGIN {FS = " to examine bug reports"}{print $1}' \
 			| awk '{ gsub("[:\47]" , ""); print $0}')
 
-	if [ -d $result_loc ]; then
+	if [ -d "$result_loc" ]; then
 		local defects="$(find $result_loc -iname 'report*.html'| wc -l)"
 		if [ $defects -ge 1 ]; then
 			echo_w "$defects defect(s) found in build \"$build_config\" "