Fix for bug 619221 - log device splitting regression

Fix for bug 619221 - log device splitting regression

An incorrect fix on July 13, 2010 for an annoyance has caused a regression.
The offending check-in was part of the 2.02.71 release of LVM.  That
check-in caused any PVs specified on the command line to be ignored when
performing a mirror split.

This patch reverses the aforementioned check-in (solving the regressions)
and posits a new solution to the list reversal problem.  The original
problem was that we would always take the lowest mimage LVs from a mirror
when performing a split, but what we really want is to take the highest
mimage LVs.  This patch accomplishes that by working through the list in
reverse order - choosing the higher numbered mimages first.  (This also
reduces the amount of processing necessary.)

Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Reviewed-by: Takahiro Yasui <takahiro.yasui@hds.com>