crypto: caam - clean-up in caam_init_rng()

Clean up the code, as indicated by Coccinelle.

Cc: Julia Lawall <[e-mail]>
Signed-off-by: Horia Geantă <[e-mail]>
Signed-off-by: Herbert Xu <[e-mail]>

drivers/crypto/caam/caamrng.c

···
 	if (err)
 		return err;
 
-	err = caam_init_buf(ctx, 1);
-	if (err)
-		return err;
-
-	return 0;
+	return caam_init_buf(ctx, 1);
 }
 
 static struct hwrng caam_rng = {