drm: Use the state pointer directly in atomic_check

Now that atomic_check takes the global atomic state as a parameter, we
don't need to go through the pointer in the CRTC state.

This was done using the following coccinelle script:

@ crtc_atomic_func @
identifier helpers;
identifier func;
@@

static struct drm_crtc_helper_funcs helpers = {
	...,
	.atomic_check = func,
	...,
};

@@
identifier crtc_atomic_func.func;
identifier crtc, state;
@@

  func(struct drm_crtc *crtc, struct drm_atomic_state *state) {
  ...
- struct drm_crtc_state *crtc_state = drm_atomic_get_new_crtc_state(state, crtc);
  ... when != crtc_state
- crtc_state->state
+ state
  ...
 }

@@
struct drm_crtc_state *crtc_state;
identifier crtc_atomic_func.func;
identifier crtc, state;
@@

  func(struct drm_crtc *crtc, struct drm_atomic_state *state) {
  ...
- crtc_state->state
+ state
  ...
 }

Suggested-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20201102133834.1176740-3-maxime@cerno.tech