net/mlx5: Fix DCT creation bad flow

net/mlx5: Fix DCT creation bad flow

In case the DCT creation command has succeeded a DRAIN must be issued
before calling DESTROY.

In addition, the original code used the wrong parameter for the DESTROY
command, 'in' instead of 'din', which caused another creation try instead
of destroying.

Cc: <[email protected]> # 4.15
Fixes: 57cda166bbe0 ("net/mlx5: Add DCT command interface")
Signed-off-by: Yishai Hadas <[email protected]>
Reviewed-by: Artemy Kovalyov <[email protected]>
Signed-off-by: Leon Romanovsky <[email protected]>
Signed-off-by: Jason Gunthorpe <[email protected]>