loopback_test: update to handle kernel sysfs layout change
loopback_test: update to handle kernel sysfs layout change

ad2591d8e72d ('loopback: fix layer violation') moved all sysfs entries to a
sub-node of the endo/interface/bundle/cport as opposed to the previous
split which contained entries in /sys/bus/greybus/devices/endo0. This patch
churns user-space to capture the new locations.

Signed-off-by: Bryan O'Donoghue <165dc05575478af93ac2f97f67be6e1756010094@linaro.org>
Signed-off-by: Greg Kroah-Hartman <4645f7897fd33786a2ee1264d590b3c400559d85@google.com>

gregkh/gbsim,gregkh/gbsim,projectara/gbsim,projectara/gbsim