dns_resolver: Null-terminate the right string

*_result[len] is parsed as *(_result[len]) which is not at all what we
want to touch here.
Signed-off-by: NBen Hutchings <ben@decadent.org.uk>
Fixes: 84a7c0b1 ("dns_resolver: assure that dns_query() result is null-terminated")
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

net/dns_resolver/dns_query.c

@@ -150,7 +150,7 @@ int dns_query(const char *type, const char *name, size_t namelen,
 		goto put;
 
 	memcpy(*_result, upayload->data, len);
-	*_result[len] = '\0';
+	(*_result)[len] = '\0';
 
 	if (_expiry)
 		*_expiry = rkey->expiry;