drm: tweak getconnector locking

We need to hold connection_mutex as we read the properties.  Easiest
thing is just widen the scope where connection_mutex is held.

Signed-off-by: Rob Clark <robdclark@gmail.com>
Reviewed-by: Sean Paul <seanpaul@chromium.org>
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

diff --cc drivers/gpu/drm/drm_crtc.c
Simple merge