Deal with killed acquire methods properly instead of hanging

Deal with killed acquire methods properly instead of hanging

This fixes a regression caussed by commit
95278287f4e1eeaf5d96749d6fc9bfc53fb400d0
that moved the error detection of RunFds() later into the loop.
However this broke detecting issues like dead acquire methods.
Instead of relying on the global error state (which is bad)
we now pass a boolean value back from RunFds() and break on
false.

Closes: #806406