rcu: Rename "empty" to "empty_norm" in preparation for boost rework

This commit undertakes a simple variable renaming to make way for
some rework of RCU priority boosting.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
This commit is contained in:
Paul E. McKenney 2014-10-30 21:08:53 -07:00
commit 74e871ac6c