mm/vmscan.c: replace printk with pr_err

This patch replaces printk(KERN_ERR..) with pr_err found under
shrink_slab.  Thus it also reduces one line extra because of formatting.
Signed-off-by: Pintu Kumar <pintu.k@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/vmscan.c

@@ -260,8 +260,7 @@ shrink_slab_node(struct shrink_control *shrinkctl, struct shrinker *shrinker,
 	do_div(delta, lru_pages + 1);
 	total_scan += delta;
 	if (total_scan < 0) {
-		printk(KERN_ERR
-		"shrink_slab: %pF negative objects to delete nr=%ld\n",
+		pr_err("shrink_slab: %pF negative objects to delete nr=%ld\n",
 		       shrinker->scan_objects, total_scan);
 		total_scan = freeable;
 	}