ieee1394: raw1394: Fix read() for 32bit userland on 64bit kernel

read() always failed with -EFAULT.  This was happening due to
raw1394_compat_read copying data to wrong location - access_ok always
failed as 'r' is kernel address, not user.  Whole function just tried to
copy data from 'r' to 'r', which is not good.

Signed-off-by: Petr Vandrovec <petr@vandrovec.name>
Acked-by: Dan Dennedy <dan@dennedy.org>
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de> (split into 3 patches)