Fix makefile warnings (typo).

Test: it builds.
Bug: b/37159108
Change-Id: Ie1ab43590ac4d08cd9bc5e3a73981404791bd7d6
Merged-In: Ie1ab43590ac4d08cd9bc5e3a73981404791bd7d6
Exempt-From-Owner-Approval: trivial makefile warning backport
2 files changed