envsetup: do not print an error if complete fails

complete is a bashism; so it will fail on other shells. Avoid printing
an error if that is the case.

Change-Id: Id6d6311792f409cc3a697c7a2bb003863f1afe60
kernel: use target strip command

Change the strip command used from the hardcoded arm
to the toolchain defined strip.

Change-Id: Id900765e8dc93af1345081f4fd0c52bebcd07fea