staging: rtl8712: r8712_set_802_11_add_wep(): Change return values

Change call sites of r8712_set_802_11_add_wep to check for 0 and
non-zero values (e.g -EINVAL, -ENOMEM) instead of for _SUCCESS and
_FAIL.
Change return values of r8712_set_802_11_add_wep from true and false and
_SUCCESS to -EINVAL and the return value of r8712_set_key.
Change return type from u8 to int to accommodate these new return
values.

Signed-off-by: Nishka Dasgupta <nishkadg.linux@gmail.com>
Link: https://lore.kernel.org/r/20190722092341.21030-6-nishkadg.linux@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

staging: rtl8712: add SPDX identifiers

This satisfies a checkpatch warning and is the preferred
method for notating the license.

The SPDX identifier is a legally binding shorthand, which
can be used instead of the full boiler plate text.

Signed-off-by: Michael Straube <straube.linux@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

staging: r8712u: Most return-values changed from -1 to proper errno macros.

The ioctl handlers were frequently returning -1 upon failure. Most of
these have now been changed to proper errno macros.
The few remaining ones have been left untouched because either the
handler is not called (and so cannot be tested), or the function never
fails (and so cannot be system-tested), or requires new code to
distinguish its failures.

Signed-off-by: Ali Bahar <ali@internetDog.org>
Cc: Larry Finger <Larry.Finger@lwfinger.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

staging: r8712u: Merging Realtek's latest (v2.6.6). Added Larry's copyright.

Larry Finger's copyright addendum has now been included in the
banners.
The files involved in this commit have had only their banners
changed; there have been no other mods.

Signed-off-by: Ali Bahar <ali@internetDog.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

staging: r8712u: Merging Realtek's latest (v2.6.6). Added copyright banners.

The only changes to these files have been the addition of only copyright
banners.

Signed-off-by: Ali Bahar <ali@internetDog.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

staging: rtl8712: fixed coding style issues

Fixed some style and format issues with headers.

Signed-off-by: Javier M. Mellid <jmunhoz@igalia.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

staging: r8712u: Add the new driver to the mainline kernel

This code is for a completely new version of the Realtek 8192 USB devices
such as the D-Link DWA-130. The Realtek code, which was originally for
Linux, Windows XP and Windows CE, has been stripped of all code not needed
for Linux. In addition, only one additional configuration variable, which
enables AP mode, remains.

Signed-off-by: Larry Finger <Larry.Finger@lwfinger.net>
Signed-off-by: Florian Schilhabel <florian.c.schilhabel@googlemail.com>
Tested-by: Frederic Leroy <fredo@starox.org>