Creating a function for this rather than having people copy/paste a loop
there.
It's very intentional that there is no timeout here. If bpfloader is
down, there is a serious problem, and we shouldn't let code move forward
in a state where it may not have been tested.
Bug: 140330870
Test: boot & use bpf/netd
Change-Id: I358d1fcf77ad5406e294dd57307bc411e2c8ad6a
4891e61341