CI: Fix style script

- when passing in more than one directory, expanded the wrong variable

ci/calamaresstyle

@@ -37,7 +37,7 @@ style_some()
 if test "x$any_dirs" = "xyes" ; then
 	for d in "$@"
 	do
-		if test -d "$@"  ; then
+		if test -d "$d"  ; then
 			style_some $( find "$d" -maxdepth 1 -type f -name '*.cpp' -o -name '*.h' )
 		else
 			style_some "$d"