external/qemu: Fix Python SyntaxWarnings

Python issues a slew of SyntaxWarnings when QEMU is built. Silence
these by fixing the two conditional expressions that generates them.

Bug: None
Test: build.py qemu-generic-test-arm64-test-debug
Change-Id: I95316663e7bddc1bf78d8bb046bbd3158ce76d68
1 file changed