adb: rationalize fatal/error logging.

Let's use LOG(FATAL)/PLOG(FATAL) for actual fatal stuff.

Add a Windows error(3) and move folks who didn't really mean "abort"
fatal over to it. Also get rid of syntax_error which wasn't adding a
lot of value, and most of the places it was adding "usage: " didn't seem
entirely appropriate anyway.

In particular, we seemed to have confused fastdeploy.cpp into aborting
in most user error cases, and none of the reviewers noticed. Clearly
we'd all lost track of far too many options.

(I've also cleaned up a few random instances of fprintf(3) + exit(2).)

Bug: N/A
Test: manual
Change-Id: I3e8440848a24e30d928de9eded505916bc324786