Final fix for obmc_boot_test ValueError.

- gen_robot_ssh.py::execute_ssh_command: sshlib.close_all_connections()
  before raise(execute_exception).  This should help subsequent
  execute_ssh_command calls succeed.

- state.py::wait_for_comm_cycle: Test for blank uptime and report it as
  communication error.  The source of the ValueError was trying to
  interpret a blank as float.

Change-Id: I1ec8dfca43397b0aca9533af55096e370d84af52
Signed-off-by: Michael Walsh <micwalsh@us.ibm.com>
2 files changed