rcu: Fix qlen_lazy breakage

Commit d8169d4c (Make __kfree_rcu() less dependent on compiler choices)
created a macro out of an inline function in order to avoid build
breakage for certain combinations of gcc flags.  Unfortunately, it also
converted a kfree_call_rcu() to a call_rcu(), which made the rcu_data
structure's ->qlen_lazy field lose counts.  This commit therefore changes
the call_rcu() back to kfree_call_rcu().

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