xprtrdma: drop double zeroing

sg_init_table zeroes its first argument, so the allocation of that argument
doesn't have to.

the semantic patch that makes this change is as follows:
(http://coccinelle.lip6.fr/)

// <smpl>
@@
expression x,n,flags;
@@

x =
- kcalloc
+ kmalloc_array
  (n,sizeof(*x),flags)
...
sg_init_table(x,n)
// </smpl>
Signed-off-by: Julia Lawall <Julia.Lawall@inria.fr>
Acked-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

net/sunrpc/xprtrdma/frwr_ops.c

@@ -124,7 +124,7 @@ int frwr_mr_init(struct rpcrdma_xprt *r_xprt, struct rpcrdma_mr *mr)
 	if (IS_ERR(frmr))
 		goto out_mr_err;
 
-	sg = kcalloc(depth, sizeof(*sg), GFP_NOFS);
+	sg = kmalloc_array(depth, sizeof(*sg), GFP_NOFS);
 	if (!sg)
 		goto out_list_err;