check_GNU_style.sh: Fix quoting in cat_with_prefix

2015-07-15  Tom de Vries  <tom@codesourcery.com>

	* check_GNU_style.sh (cat_with_prefix): Fix quoting.

From-SVN: r225837

contrib/ChangeLog

+2015-07-15  Tom de Vries  <tom@codesourcery.com>
+
+	* check_GNU_style.sh (cat_with_prefix): Fix quoting.
+
 2015-06-02  Steve Ellcey  <sellcey@imgtec.com>
 
 	* test_installed (--target=): New option.

contrib/check_GNU_style.sh

@@ -89,7 +89,7 @@ cat_with_prefix ()
     if [ "$prefix" = "" ]; then
 	cat "$f"
     else
-	awk "{printf "%s%s\n", $prefix, \$0}" $f
+	awk "{printf \"%s%s\n\", \"$prefix\", \$0}" $f
     fi
 }