staging: exfat: Clean up return codes - FFS_ERROR

Convert FFS_ERROR to -EINVAL

Signed-off-by: Valdis Kletnieks <Valdis.Kletnieks@vt.edu>
Link: https://lore.kernel.org/r/20191112021000.42091-6-Valdis.Kletnieks@vt.edu
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
3 files changed