Move the code that deals with setting up each individual button out into
a new function to reduce the indentation and allow us to common up some
of the error recovery code.
Signed-off-by: NBen Dooks <ben@simtec.co.uk>
Signed-off-by: NSimtec Linux Team <linux@simtec.co.uk>
Signed-off-by: NDmitry Torokhov <dtor@mail.ru>