net/sunrpc: return 0 on attempt to write to "transports"

You can't write to this file because the permissions are 0444. But
it sort of looked like you could do a write and it would result in
a read. Then it looked like proc_sys_call_handler() just ignored
it. Which is confusing. It's more clear if the "write" just
returns zero.

Also, the "lenp" pointer is never NULL so that check can be removed.

Signed-off-by: Dan Carpenter <[e-mail]>
Signed-off-by: J. Bruce Fields <[e-mail]>

net/sunrpc/sysctl.c

···
 	char tmpbuf[256];
 	size_t len;
 
-	if ((*ppos && !write) || !*lenp) {
+	if (write || *ppos) {
 		*lenp = 0;
 		return 0;
 	}