Staging: rtl8712: remove unused functions

Staging: rtl8712: remove unused functions

Remove the functions sleep_schedulable, down_scanned_network,
up_scanned_network and get_free_xmit_queue as they are not used anywhere
in the kernel. Functions detected using coccinelle but changes done by
hand.
Script:

@initialize:python@
@@
def display(name,p):
        print(name,p[0].file)

@r1@
identifier func;
type T;
position p;
@@
static T func@p(...)
{
...
}

@r@
identifier r1.func;
@@
func

@script:python depends on !r@
func << r1.func;
p << r1.p;
@@
display(func,p)

Signed-off-by: Bhumika Goyal <bhumirks@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>