RDMA/ucma: Check that user doesn't overflow QP state

commit a5880b84 upstream.

The QP state is limited and declared in enum ib_qp_state,
but ucma user was able to supply any possible (u32) value.

Reported-by:  <syzbot+0df1ab766f8924b1edba@syzkaller.appspotmail.com>
Fixes: 75216638 ("RDMA/cma: Export rdma cm interface to userspace")
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>