wusbcore: dev-sysfs: use permission-specific DEVICE_ATTR variants

Use DEVICE_ATTR_WO for write ony attributes and DEVICE_ATTR_RO for read
only attributes.  This simplifies the source code, improves readbility,
and reduces the chance of inconsistencies.

The semantic patch for the RO case is as follows:
(http://coccinelle.lip6.fr/

)

// <smpl>
@ro@
declarer name DEVICE_ATTR;
identifier x,x_show;
@@

DEVICE_ATTR(x, \(0444\|S_IRUGO\), x_show, NULL);

@script:ocaml@
x << ro.x;
x_show << ro.x_show;
@@

if not (x^"_show" = x_show) then Coccilib.include_match false

@@
declarer name DEVICE_ATTR_RO;
identifier ro.x,ro.x_show;
@@

- DEVICE_ATTR(x, \(0444\|S_IRUGO\), x_show, NULL);
+ DEVICE_ATTR_RO(x);
// </smpl>

Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>