shared: fail reading a directory as a config file

open() will happily open directories and other non-normal files.
Attempting to parse them as config files makes no sense, so check that
the opened file is indeed a regular file.

Signed-off-by: Pekka Paalanen <pekka.paalanen@collabora.co.uk>
Reviewed-by: Jonny Lamb <jonny.lamb@collabora.co.uk>
Reviewed-by: Nobuhiko Tanibata <NOBUHIKO_TANIBATA@xddp.denso.co.jp>
Reviewed-by: Bryce Harrington <bryce@osg.samsung.com>
1 file changed