Fix the build after breaking it in r285549.

I performed the commit on a different system as where I wrote the
change. After pulling in the change from Phabricator, I didn't notice
that a single chunk did not apply.

Approved by:	secteam (implicit, as intended change was approved)
Pointy hat to:	me

sys/dev/random/randomdev.c

@@ -168,7 +168,7 @@ read_random_uio(struct uio *uio, bool nonblock)
 	/* (Un)Blocking logic */
 	error = 0;
 	while (!random_alg_context.ra_seeded()) {
-		if (flags & O_NONBLOCK)	{
+		if (nonblock) {
 			error = EWOULDBLOCK;
 			break;
 		}