passfd_setup: Configure the compiler

In order to pull cross-compilation information from the environment, the
compiler needs to be customized.

Signed-off-by: Jonas Eriksson <jonas.eriksson@enea.com>
utils_netperf: Avoid building if binary installed

Before trying to build netperf and netserver, try to check if the
binaries are already available on the host.

Signed-off-by: Jonas Eriksson <jonas.eriksson@enea.com>
Merge pull request #1580 from zqad/build-avoidance

Build avoidance (pass_fd.so, netperf)