test: update result file for unit/fiber_stack test

This commit follows up the previous one (i.e. the backport of the commit
ff57f990 ("cmake: introduce FIBER_STACK_SIZE option")), since the
commit 98f62cd0 ("test: make fiber_stack.test tap-compatible") and
its siblings have not been backported to 2.10 in scope of #7618.

NO_DOC=fixup for d296f732
NO_CHANGELOG=fixup for d296f732