Linux 3.16 compat: remove wait_on_bit action function

Linux kernel 3.16 removes the action function argument
from wait_on_bit().  Add autoconf test and compatibility
macro to support new interface.

References:
	torvalds/linux@7431620

Signed-off-by: Ned Bass <bass6@llnl.gov>

Closes zfsonlinux/spl#378