Remove a useless variable

Remove a useless variable

Note that it's quite important to put the variables and the check inside
of the pipeline. This is because the shell is allowed to run the pipeline
command in a subshell (here done explicitly, but even if we wouldn't put
an explicit subshell the shell could create one), and therefore not
propagate the changes outside, making the test useless.

Change-Id: Ie3bd27e38bbe88ede1b7dfcf63639befa0b47486