RDMA/mlx5: Remove unneeded semicolon

A semicolon is not needed after a switch statement.

Link: https://lore.kernel.org/r/20201031134638.2135060-1-trix@redhat.com


Signed-off-by: Tom Rix <trix@redhat.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>