core/tests: correctly store the threads exit codes
core/tests: correctly store the threads exit codes

The exit codes are defined as ints, while we were using an bool array.
This resulted in stack corruption due to the difference of the size in
the two types.

Huge thanks to Jose for spotting this one.

Spotted-by: Jose Fonseca <61b5a29db2c0650f7c8510f93eece059c1b09320@vmware.com>
Signed-off-by: Emil Velikov <4c996f2f093ddd0585a556460b4cc3ba555546ef@gmail.com>

chadversary/waffle,waffle-gl/waffle,maurossi/waffle,fjhenigman/waffle,fjhenigman/waffle,maurossi/waffle,evelikov/waffle,fjhenigman/waffle,dcbaker/waffle,dcbaker/waffle,evelikov/waffle,chadversary/waffle,maurossi/waffle,waffle-gl/waffle,chadversary/waffle,dcbaker/waffle,waffle-gl/waffle,evelikov/waffle,waffle-gl/waffle