This is required since pollers are now directly removed
(rather than scheduling an event) when the unregister call
is made on the poller's lcore.
Without this change, if a poller is registered then
immediately unregistered, the unregistration will seg
fault since the event adding the poller has not executed
yet.
Also add a test case that exhibits the sequence of events
described in this commit message.
Signed-off-by: Jim Harris <james.r.harris@intel.com>
Change-Id: I5c6ba0ee224ac1f8f3ebb8e7571714e718bd42db
d4d82fc3ab