arch/tile: check kmalloc() result

If kmalloc() fails exit with -ENOMEM.

Signed-off-by: Kulikov Vasiliy <[e-mail]>
Acked-by: Chris Metcalf <[e-mail]>

arch/tile/kernel/hardwall.c

···
 	/* Allocate a new rectangle optimistically. */
 	rect = kmalloc(sizeof(struct hardwall_info),
 			GFP_KERNEL | __GFP_ZERO);
+	if (rect == NULL)
+		return ERR_PTR(-ENOMEM);
 	INIT_LIST_HEAD(&rect->task_head);
 
 	/* Compute the rectangle size and validate that it's plausible. */