Simpleperf: rewrite unsupported logging style.

Simpleperf: rewrite unsupported logging style.

Previously we can use a ternary operator to choose the log level, like
(error ? LOG(ERROR) : LOG(DEBUG)) << xxx. But as the LOG() macro is about
to change, we can no longer write like this.

This CL also changes some improper log levels and log messages.

Change-Id: Ib9a55f2ca241516a6e89afad4a733cc07b19570f