smbd: consolidate fs capabilities code in vfswrap_fs_capabilities()

smbd: consolidate fs capabilities code in vfswrap_fs_capabilities()

This ensures the values we return via SMB_FS_ATTRIBUTE_INFORMATION is the same
we use internally via conn->fs_capabilities.

This deliberately preserves existing behaviour as much as possible and leaves
possible improvements as a future excercize. Particularily FILE_VOLUME_QUOTAS is
already set insided SMB_VFS_STATVFS() depending on backend filesystem flags
which is probably the correct way to do it instead of just setting the
capability when Samba was built with quota support.

BUG: https://bugzilla.samba.org/show_bug.cgi?id=15822

Signed-off-by: Ralph Boehme <slow@samba.org>
Reviewed-by: David Disseldorp <ddiss@samba.org>
(cherry picked from commit deeca8ff176e7e9082cc0fcf48d7f981de2523c5)