Fix get build log offset

build.log file size test fails due to ${OFFSET} replace by nothing.

$ of OFFSET variable substitution should be escaped to be used in the resulting job script, instead of being replaced by nothing during job creation.

We can't use multiplier suffix for MAX_BUILDLOG_SIZE as it is used in arithmetic substitution.

Signed-off-by: Frédéric Danis frederic.danis@collabora.com