arch/ppc64/kernel/mf_proc.c uses a bad interface for moving along file
position in a proc_write routine.  This quit working altogether in 2.6.8.
Patch to fix.  And I did a quick scan of the kernel to see if anyone else
was similarly broken...apparantly not :-)

Fixes a broken update of f_pos in a proc file write routine.
Signed-off-by: Dave Boutcher <sleddog@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>