CIFS: Show backupuid/gid in /proc/mounts

Show  backupuid/backupgid in /proc/mounts for cifs shares mounted with
the backupuid/backupgid feature.

Also consolidate the two separate checks for
pvolume_info->backupuid_specified into a single if condition in
cifs_setup_cifs_sb().

Signed-off-by: Sachin Prabhu <sprabhu@redhat.com>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>

fs/cifs/cifsfs.c

@@ -434,6 +434,10 @@ cifs_show_options(struct seq_file *s, struct dentry *root)
 		seq_printf(s, ",noperm");
 	if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_STRICT_IO)
 		seq_printf(s, ",strictcache");
+	if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_CIFS_BACKUPUID)
+		seq_printf(s, ",backupuid=%u", cifs_sb->mnt_backupuid);
+	if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_CIFS_BACKUPGID)
+		seq_printf(s, ",backupgid=%u", cifs_sb->mnt_backupgid);
 
 	seq_printf(s, ",rsize=%d", cifs_sb->rsize);
 	seq_printf(s, ",wsize=%d", cifs_sb->wsize);