xmlconfig: fix scandir_filter

this was changed from a fnmatch usage to strcmp, and the return value
was flipped, breaking matching

also fix the formatting of the changed lines

Fixes: 4f37161a8f2: ("util/xmlconfig: Indent to Mesa style.")

Reviewed-by: Eric Anholt <eric@anholt.net>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/7018>
1 file changed