RDMA/ucma: Correct option size check using optlen

RDMA/ucma: Correct option size check using optlen

[ Upstream commit 5f3e3b85cc0a5eae1c46d72e47d3de7bf208d9e2 ]

The option size check is using optval instead of optlen
causing the set option call to fail. Use the correct
field, optlen, for size check.

Fixes: 6a21dfc0d0db ("RDMA/ucma: Limit possible option size")
Signed-off-by: Chien Tin Tung <chien.tin.tung@intel.com>
Signed-off-by: Shiraz Saleem <shiraz.saleem@intel.com>
Reviewed-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>