bdev could be unregistered multiple times when all it's descriptors have
been instantly closed via it's remove_cb without any deferred
event/poller
Change-Id: I128716077b0512c6334bdd113220684f8cfcbecb
Signed-off-by: Dariusz Stojaczyk <dariuszx.stojaczyk@intel.com>
Reviewed-on: https://review.gerrithub.io/370949
Tested-by: SPDK Automated Test System <sys_sgsw@intel.com>
Reviewed-by: Daniel Verkamp <daniel.verkamp@intel.com>
Reviewed-by: Ben Walker <benjamin.walker@intel.com>
Reviewed-by: Jim Harris <james.r.harris@intel.com>
f84616102b