cifs: populate server_hostname for extra channels

Recently, a new field got added to the smb3_fs_context struct
named server_hostname. While creating extra channels, pick up
this field from primary channel.
Signed-off-by: Shyam Prasad N <sprasad@microsoft.com>
Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: Steve French <stfrench@microsoft.com>

fs/cifs/sess.c

@@ -222,6 +222,7 @@ cifs_ses_add_channel(struct cifs_sb_info *cifs_sb, struct cifs_ses *ses,
 	/* Auth */
 	ctx.domainauto = ses->domainAuto;
 	ctx.domainname = ses->domainName;
+	ctx.server_hostname = ses->server->hostname;
 	ctx.username = ses->user_name;
 	ctx.password = ses->password;
 	ctx.sectype = ses->sectype;