bsdiff: Change all stderr and perror to LOG(ERROR)

We need to be able to turn off the logging at runtime. When performing fuzz
testing, the input data is mostly invalid. But the invalid input data causes all
the error logs in the output which is noisy, inefficient, and not
necessary. More information can be found in:
https://chromium.googlesource.com/chromium/src/+/master/testing/libfuzzer/getting_started.md#disable-noisy-error-message-logging

One option to turn off the logging at runtime is:

std::cerr.setstate(std::ios_base::failbit);

which works but not when we are doing fprintf to stderr. Another option
is in the lines of the following:

freopen("/dev/null", "w", stderr);

But, this seem to disable everything even useful needed logs.

This patch, changes all codes (except in bsdiff_main.cc) that logs using
fprintf() and perror() to the new uniform form of logging (defined in
logging.h). This new logging alternative allows universal manipulation of the
logging if necessary.

Bug: none
Test: unittests pass

Change-Id: I42bb3e5856c5c215dd82925ccdca44556124655d