linux-imx

rcu: Remove unused variable from rcu_torture_writer()

The oldbatch variable in rcu_torture_writer() is stored to, but never
loaded from.  This commit therefore removes it.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>