[PATCH] Doc/MSI-HOWTO: cleanups

Clean up typos, kernel function interfaces, acronyms, add whitespace,
improve readability.
Signed-off-by: NRandy Dunlap <rdunlap@xenotime.net>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>