ext2: Fix checkpatch violations

Fix all checkpatch violations in the low level Ext2 block
device reading code.  This is done in preparation for cleaning
up the partial sector access code.

Signed-off-by: Anton Staaf <robotboy@chromium.org>
Cc: Andy Fleming <afleming@freescale.com>
Acked-by: Detlev Zundel <dzu@denx.de>