Followup I2dd1c60e3bfd9c823a7382b1390b1d40c52a5c97.
The 'wait_for' array always updated even the command not executed
after test because of '&' control operator, so lets wrap construction
in standard 'if..then' case instead of using '&&' control operator.
Change-Id: I1d1ecb05e61f3995a98de450705451b94b437a08
Signed-off-by: Maksim Malchuk <maksim.malchuk@gmail.com>