srcu: Make exp_holdoff module parameter be static

Because exp_holdoff is not used outside of srcutree.c, it can be static.
This commit therefore makes this change.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
This commit is contained in:
Paul E. McKenney 2017-04-28 11:20:29 -07:00
commit b5815e6cd3