[media] wm8775: fix broken audio routing

[media] wm8775: fix broken audio routing

Commit 5aa9ae5ed5d449a85fbf7aac3d1fdc241c542a79 inverted the mute control
state test in s_routing which caused the audio routing to fail. This broke
ivtv support for the Hauppauge video/audio input bracket (which adds additional
video and audio inputs) all the way back in kernel 2.6.36.
This fix fixes the condition and it also removes a nonsense check on the
balance control.
Bisected-by: Rajil Saraswat <rajil.s@gmail.com>
Signed-off-by: Andy Walls <awalls@md.metrocast.net>
Reported-by: Rajil Saraswat <rajil.s@gmail.com>
Tested-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Cc: stable@vger.kernel.org      # for v3.10 and up
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>