cifs: remove unneeded bcc_ptr update in CIFSTCon

This pointer isn't used again after this point. It's also not updated in
the ascii case, so there's no need to update it here.

Pointed-out-by: Dave Kleikamp <shaggy@linux.vnet.ibm.com>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>