Split the cylinder pressure analysis into a second loop

Split the cylinder pressure analysis into a second loop

For the dive computers that give cylinder change events, we want to
re-write the cylinder index and pressure information with the event
information before we start analyzing the pressures.  So instead of
filling the plot info and analyzing in one loop, split it up into two
phases.  We'll do the "fix up cylinder pressure info based on events" in
between those phases.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>