UPSTREAM: staging/gdm72xx: Remove unused variable in gdm_qos.c

UPSTREAM: staging/gdm72xx: Remove unused variable in gdm_qos.c

len is never read after assignment, thus can be removed.

Signed-off-by: Peter Huewe <peterhuewe@gmx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
(cherry picked from commit eb986df15c86b66a51f6e82f4706bc825444670b)

Change-Id: I23e845226e446fb1cbc8568949be0d956baf350b
Signed-off-by: Ben Chan <benchan@chromium.org>
Reviewed-on: https://gerrit.chromium.org/gerrit/49425
Reviewed-by: Paul Stewart <pstew@chromium.org>
Reviewed-by: Olof Johansson <olofj@chromium.org>