The current kernel rpm scriptlets have some room for optimization.  Most
notably, the initrd creation and boot loader setup are called at %post, and
those can be postponed to %posttrans instead.

The problem of multiple initrd creations and boot loader setups becomes more
significant when another package touching initrd (e.g. coreutils) is installed
together, or when the split kernel (kernel-default-extra) is installed
together.  As the initrd and the bootloeader setup are triggered in %post from
both kernel-default and kernel-default-extra while the re-creation of the all
initrd is triggered by another package update, this will end up two more extra
calls that are superfluous.

In addition to the above, the pre.sh script contains a few almost superfluous
checks no one really cares.  We may clean them up, too.