ci.jpl: Only run performance.py in tf-m-nightly-performance job

There is no performance related log files in other jobs than
tf-m-nightly-performance job. To avoid unexpected errors, only run
performance.py in tf-m-nightly-performance job.

Signed-off-by: Xinyu Zhang <xinyu.zhang@arm.com>
Change-Id: Ia815700f71ca41d36a4432193544d2beb337e564
1 file changed