[PATCH] mmc: properly use the new multi block-write error handling

Use the new multi block-write error reporting flag and properly tell the block
layer how much data was transferred before the error.

Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
Cc: Russell King <rmk@arm.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>