Move OBMC_TOOLS_BASE_DIR_PATH assignment
Move OBMC_TOOLS_BASE_DIR_PATH assignment

- Move OBMC_TOOLS_BASE_DIR_PATH from robot_cmd_fnc to
  init_robot_test_base_dir_path.  This is a more appropriate place for
  the assignment as it can now be used by callers who don't necessarily
  need robot_cmd_fnc.

- Change openbmctool_dir_path to OPENBMCTOOL_DIR_PATH to indicate that
  it is a global variable.

- Set MSBARTH_TOOLS_DIR_PATH.

Change-Id: Id39a977ab2d133bfc00598c03f7888295bd2ded6
Signed-off-by: Michael Walsh <10404802c7de463f402c4a18638106ca1b12ef61@us.ibm.com>

openbmc/openbmc-test-automation,openbmc/openbmc-test-automation