staging: rtl8712: reduce stack usage

The "translate_scan" function in rtl8712 uses a lot of stack, and
gets inlined into its single caller, r8711_wx_get_scan, which
in some configurations now blows the 1024 byte stack warning
limit:

drivers/staging/rtl8712/rtl871x_ioctl_linux.c: In function 'r8711_wx_get_scan':
drivers/staging/rtl8712/rtl871x_ioctl_linux.c:1227:1: error: the frame size of 1032 bytes is larger than 1024 bytes [-Werror=frame-larger-than=]

This somewhat reduces the stack usage by moving the translate_scan
function out of line with the noinline_for_stack annotation.
It might be possible to modify translate_scan() a little further
to reduce the stack usage, but with this patch, we can build without
the warning, the the call chain to get here is rather predictable
(sys_ioctl->vfs_ioctl->sock_ioctl->dev_ioctl->wext_ioctl->
r8711_wx_get_scan).

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Larry Finger <Larry.Finger@lwfinger.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>