Now that cond_resched() also provides RCU quiescent states when
needed, it can be used in place of cond_resched_rcu_qs().  This
commit therefore makes this change.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Ingo Molnar <mingo@redhat.com>