net/mlx5: Avoid blank lines before/after closing/opening braces

Fixed checkpatch complaints on that:

 CHECK: Blank lines aren't necessary before a close brace '}'
 CHECK: Blank lines aren't necessary after an open brace '{'

and one on missing blank line..

Signed-off-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>