smb: client: fix warning in generic_ip_connect()

This fixes the following warning reported by kernel test robot

  fs/smb/client/connect.c:2974 generic_ip_connect() error: we
  previously assumed 'socket' could be null (see line 2962)

Link: https://lore.kernel.org/all/202306170124.CtQqzf0I-lkp@intel.com/


Signed-off-by: Paulo Alcantara (SUSE) <pc@manguebit.com>
Signed-off-by: Steve French <stfrench@microsoft.com>