InstallUtil: Fix failure of configure N/W when ping_network fails
InstallUtil: Fix failure of configure N/W when ping_network fails

get_server_ip tries to ping first, if that fails, then it calls
assign_ip_petitboot and then re-check for ping_network.

But ping_network fails to raise exception when the re-try count
reached to one. Due to which n/w configuration is not triggered
properly.

This fixes by raising a CommandFailed exception when re-try count
reaches to one.

Signed-off-by: Pridhiviraj Paidipeddi <fd8ea14509c256cbd04eaa4ee745a213945e70a1@linux.vnet.ibm.com>

open-power/op-test-framework,open-power/op-test-framework,open-power/op-test-framework