Fix race condition and logging

The extra `defer os.Remove(fifo)` was sometimes racing with the next
instance of ninja, removing the file in between when it was re-created
and used. Since we're always removing the file before creating it, it's
safe to just remove that.

The error message for this failure wasn't all that good either, so move
so use the status Print/Error calls inside the goroutine instead of the
logging ones.

Test: `build/soong/build_test.bash -only-soong` repeatedly
Change-Id: Icfeb6b68802093bd3a07d3e46046ef7d1a89d4a1