linux-phytec-ti

rcu: Don't scan root rcu_node structure for stalled tasks

Now that blocked tasks are no longer migrated to the root rcu_node
structure, there is no need to scan the root rcu_node structure for
blocked tasks stalling the current grace period.  This commit therefore
removes this scan.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>