cxgb4: kfree mhp after the debug print

In function `c4iw_dealloc_mw`, variable mhp's value is printed after
freed, it is clearer to have the print before the kfree.

Otherwise racing threads could allocate another mhp with the same pointer
value and create confusing tracing.
Signed-off-by: NShaobo He <shaobo@cs.utah.edu>
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>

drivers/infiniband/hw/cxgb4/mem.c

@@ -678,8 +678,8 @@ int c4iw_dealloc_mw(struct ib_mw *mw)
 			  mhp->wr_waitp);
 	kfree_skb(mhp->dereg_skb);
 	c4iw_put_wr_wait(mhp->wr_waitp);
-	kfree(mhp);
 	pr_debug("ib_mw %p mmid 0x%x ptr %p\n", mw, mmid, mhp);
+	kfree(mhp);
 	return 0;
 }