RDMA/restrack: Release MR restrack when delete

The MR restrack also needs to be released when delete it, otherwise it
cause memory leak as the task struct won't be released.

Fixes: 13ef5539 ("RDMA/restrack: Count references to the verbs objects")
Signed-off-by: Mark Zhang <markzhang@nvidia.com>
Reviewed-by: Michael Guralnik <michaelgur@nvidia.com>
Link: https://lore.kernel.org/r/703db18e8d4ef628691fb93980a709be673e62e3.1667810736.git.leonro@nvidia.comSigned-off-by: Leon Romanovsky <leon@kernel.org>

drivers/infiniband/core/restrack.c

@@ -343,8 +343,6 @@ void rdma_restrack_del(struct rdma_restrack_entry *res)
 	rt = &dev->res[res->type];
 
 	old = xa_erase(&rt->xa, res->id);
-	if (res->type == RDMA_RESTRACK_MR)
-		return;
 	WARN_ON(old != res);
 
 out: