cifs: update cifs_ses::ip_addr after failover

cifs_ses::ip_addr wasn't being updated in cifs_session_setup() when
reconnecting SMB sessions thus returning wrong value in
/proc/fs/cifs/DebugData.

Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Cc: stable@kernel.org
Signed-off-by: Steve French <stfrench@microsoft.com>