MTD: Fatal regression in drivers/mtd/redboot.c in 2.6.20

MTD: Fatal regression in drivers/mtd/redboot.c in 2.6.20

[MTD] Fix regression in RedBoot partition scanning

This fixes a regression introduced by the attempt to handle RedBoot FIS
tables which are smaller than an eraseblock, in commit
0b47d654089c5ce3f2ea26a4485db9bcead1e515

It moves the recalculation of the number of slots in the table to the
correct place, and improves the heuristic for when we think we need to
byte-swap what we read from the flash.

Signed-off-by: David Woodhouse <dwmw2@infradead.org>
Cc: Rod Whitby <rod@whitby.id.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>