When unaligned writes are used, typically doing a cp file /dev/mtdraw0.foo,
the alignement correction code was incorrectly handling such cases, and
didn't return the expected number of written bytes.
This was tested on a 528 block size.
Signed-off-by: Robert Jarzmik <robert.jarzmik@free.fr>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>