Commit 
fbe77c30e9ab ("NFS: move rw_mode to nfs_pageio_header")
reintroduced some pointless code that commit 
518662e0fcb9 ("NFS: fix
usage of mempools.") had recently removed.
Remove it again.
Cc: Benjamin Coddington <bcodding@redhat.com>
Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
 
 {
        struct nfs_pgio_header *p = mempool_alloc(nfs_wdata_mempool, GFP_NOIO);
 
-       if (p) {
-               memset(p, 0, sizeof(*p));
-               p->rw_mode = FMODE_WRITE;
-       }
+       memset(p, 0, sizeof(*p));
+       p->rw_mode = FMODE_WRITE;
        return p;
 }