[PATCH] uml: line_setup interface change

line_setup is changed to return the device which it set up, rather than just
success or failure.  This will be important in the line-config patch.

Signed-off-by: Jeff Dike <jdike@addtoit.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>