mpt fusion: convert to seq_file

Convert everything except ->proc_info() stuff, it is done within separate
->proc_info path series.

Problem with ->read_proc et al is described here commit
786d7e16 "Fix rmmod/read/write races in
/proc entries"

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Eric Moore <Eric.Moore@lsi.com>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>