tfa-next: don't override RUSTUP_HOME for local CI runs

When running CI locally, RUSTUP_HOME should not be set to
/usr/local/rustup as it's currently being done.
It should be updated to /usr/local/rustup only when running on
jenkins.

Change-Id: I706eaf006ad4a4409a86fea02c969e9127a43cea
Signed-off-by: Tomás González <tomasagustin.gonzalezorlando@arm.com>
2 files changed