The userspace memory region 'mr' is allocated with kzalloc in
__rvt_alloc_mr  however it is incorrectly being freed with vfree in
__rvt_free_mr. Fix this by using kfree to free it.
Signed-off-by: NColin Ian King <colin.king@canonical.com>
Reviewed-by: NLeon Romanovsky <leonro@mellanox.com>
Acked-by: NDennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: NDoug Ledford <dledford@redhat.com>