Style fixes in XIA code

These patches contain some style fixes to satisfy scripts/checkpatch.pl. There are still some errors, warnings, and checks reported by checkpatch, but in my opinion they are either false positives or inappropriate changes to make.

The only outstanding warnings that really *could* be changed are the warnings related to the chunks of code in the Serval principal that are commented-out. However, many of these chunks are in place for future reference; they have comments like "use this code to determine how to do XXX." Other chunks that have to do with metrics that are currently commented out may be able to be removed; I don't know how valuable those pieces of code are, and whether it's worth removing them just to satisfy checkpatch.