oeqa/tinfoil: Improve test_wait_event for race issues
The test could break in a variety of ways:
a) If BB_HEARTBEAT_EVENT was less than ~0.25 it would hang indefinitely
b) The mask is set after draining the event queue meaning a heartbeat event
could have happened
c) The test exits once it sees the events it wants, it doesn't check for
spurious events such as heartbeats which shouldn't have occured.
d) The hardcoded delay of 0.25 is nasty and shouldn't be needed.
I found a bitbake bug and fixed that meaning we don't need the delay any
more which fixes d). That means a) is no longer an issue either.
We now set the mask, then drain the queue meaning no spurious events should
be able to sneak in. The test is also tweaked to wait for 5s in total to
ensure spurious events don't occur such as heartbeat events we shouldn't see.
[YOCTO #11045]
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
