SUNRPC: remove pointless test in unx_match()

As reported by Dan Carpenter, this test for acred->cred being set is
inconsistent with the dereference of the pointer a few lines earlier.

An 'auth_cred' *always* has ->cred set - every place that creates one
initializes this field, often as the first thing done.

So remove this test.
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>

net/sunrpc/auth_unix.c

@@ -87,7 +87,7 @@ unx_match(struct auth_cred *acred, struct rpc_cred *cred, int flags)
 	if (!uid_eq(cred->cr_cred->fsuid, acred->cred->fsuid) || !gid_eq(cred->cr_cred->fsgid, acred->cred->fsgid))
 		return 0;
 
-	if (acred->cred && acred->cred->group_info != NULL)
+	if (acred->cred->group_info != NULL)
 		groups = acred->cred->group_info->ngroups;
 	if (groups > UNX_NGROUPS)
 		groups = UNX_NGROUPS;