tests: skip bpf filter test on syscall error
tests: skip bpf filter test on syscall error

Bug-Url: https://github.com/svinota/pyroute2/pull/150
tomislacker/python-iproute2,simudream/pyroute2,vodik/pyroute2,little-dude/pyroute2,drzaeus77/pyroute2,roolebo/pyroute2,nazarewk/pyroute2,tomislacker/python-iproute2,little-dude/pyroute2,mtiny/pyroute2,little-dude/pyroute2,simudream/pyroute2,nazarewk/pyroute2,mtiny/pyroute2,roolebo/pyroute2,drzaeus77/pyroute2,nazarewk/pyroute2,vodik/pyroute2