dexopt: Fix target-sdk-version argument creation

Refactor CL I8fdf96cfe0343042d1a868ca09e6c6b9a629b967 has a typo
which leaves the target-sdk-version argument of dex2oat always empty.
Fix the issue.

Test: manual inspection of command line arguments
Change-Id: Ibeff04758dabacf4ea04fd9e54976798fcba10f1
1 file changed