Remove redundant call to set the vinctrl register.  This eliminates any
ambiguity as to how the register is configured (since it is now always set in
em28xx_set_outfmt).

This work was sponsored by EyeMagnet Limited.
Signed-off-by: Devin Heitmueller <dheitmueller@kernellabs.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>