This enables using SPDK within a larger process that
is SPDK-centric. In this case the process may start
SPDK and then wish to stop it explicitly (without a
signal).
While here, remove an incorrect comment - DPDK mempools
can be used from non-DPDK threads. Also set the
g_shutdown_event to NULL after it is called. After the
event executes, the event is freed and is no longer valid.
Signed-off-by: Jim Harris <james.r.harris@intel.com>
Change-Id: Ie4f07bee7d05fae683c72f6680cb3bcce2d4a119