Fix recovery image text rendering.

Previously most devices would lose the character before a line wrap.
The log's text rendering was starting at offset 4 but none of the
arithmetic was taking this into account. It just happened to work
on the Nexus 9's 1536-pixel wide display (1536/18=85.3) but not on
a device such as the Nexus 5 (1080/18=60).

The only active part of this change is the change from 4 to 0 in the
gr_text call. The rest is just a few bits of trivial cleanup while I
was working out what was going on.

Change-Id: I9279ae323c77bc8b6ea87dc0fe009aaaec6bfa0e