USB: gadget: audit sysfs attribute permissions

Convert all USB gadget sysfs attributes to use the _RO or _RW variants,
to make them easier to audit and ensure that the permissions are
correct.

Note, two are left using the DEVICE_ATTR() macro, as there is no
DEVICE_ATTR_WO() in Linus's tree, that will happen after 3.12-rc1 is
out, a follow-on patch will be sent then.

Reviewed-by: Felipe Balbi <balbi@ti.com>
Acked-by: Felipe Balbi <balbi@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

--
 drivers/usb/gadget/composite.c      |    8 +++-----
 drivers/usb/gadget/dummy_hcd.c      |    8 ++++----
 drivers/usb/gadget/f_mass_storage.c |   14 ++++++--------
 drivers/usb/gadget/net2272.c        |    4 ++--
 drivers/usb/gadget/net2280.c        |   18 +++++++++---------
 drivers/usb/gadget/storage_common.c |   25 ++++++++++++-------------
 drivers/usb/gadget/udc-core.c       |   14 +++++++-------
 7 files changed, 43 insertions(+), 48 deletions(-)
7 files changed