smb: client: fix dir separator in SMB1 UNIX mounts

smb: client: fix dir separator in SMB1 UNIX mounts

When calling cifs_mount_get_tcon() with SMB1 UNIX mounts,
@cifs_sb->mnt_cifs_flags needs to be read or updated only after
calling reset_cifs_unix_caps(), otherwise it might end up with missing
CIFS_MOUNT_POSIXACL and CIFS_MOUNT_POSIX_PATHS bits.

This fixes the wrong dir separator used in paths caused by the missing
CIFS_MOUNT_POSIX_PATHS bit in cifs_sb_info::mnt_cifs_flags.

Reported-by: "Kris Karas (Bug Reporting)" <bugs-a21@moonlit-rail.com>
Closes: https://lore.kernel.org/r/f758f4ff-4d54-4244-931d-38f469c3ff14@moonlit-rail.com
Fixes: 4fc3a433c139 ("smb: client: use atomic_t for mnt_cifs_flags")
Signed-off-by: Paulo Alcantara (Red Hat) <pc@manguebit.org>
Cc: David Howells <dhowells@redhat.com>
Cc: linux-cifs@vger.kernel.org
Cc: stable@vger.kernel.org
Signed-off-by: Steve French <stfrench@microsoft.com>