rcu: Convert rcutree.c printk calls

This commit converts printk() calls to the corresponding pr_*() calls.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
diff --git a/kernel/rcutree.c b/kernel/rcutree.c
index 3538001..1009c0c 100644
--- a/kernel/rcutree.c
+++ b/kernel/rcutree.c
@@ -866,7 +866,7 @@
 	 * See Documentation/RCU/stallwarn.txt for info on how to debug
 	 * RCU CPU stall warnings.
 	 */
-	printk(KERN_ERR "INFO: %s detected stalls on CPUs/tasks:",
+	pr_err("INFO: %s detected stalls on CPUs/tasks:",
 	       rsp->name);
 	print_cpu_stall_info_begin();
 	rcu_for_each_leaf_node(rsp, rnp) {
@@ -899,7 +899,7 @@
 	       smp_processor_id(), (long)(jiffies - rsp->gp_start),
 	       rsp->gpnum, rsp->completed, totqlen);
 	if (ndetected == 0)
-		printk(KERN_ERR "INFO: Stall ended before state dump start\n");
+		pr_err("INFO: Stall ended before state dump start\n");
 	else if (!trigger_all_cpu_backtrace())
 		rcu_dump_cpu_stacks(rsp);
 
@@ -922,7 +922,7 @@
 	 * See Documentation/RCU/stallwarn.txt for info on how to debug
 	 * RCU CPU stall warnings.
 	 */
-	printk(KERN_ERR "INFO: %s self-detected stall on CPU", rsp->name);
+	pr_err("INFO: %s self-detected stall on CPU", rsp->name);
 	print_cpu_stall_info_begin();
 	print_cpu_stall_info(rsp, smp_processor_id());
 	print_cpu_stall_info_end();