drm/i915: remove redundant variable hw_check

hw_check is being assigned and updated but is no longer being read,
hence it is redundant and can be removed.

Detected by clang scan-build:
"warning: Value stored to 'hw_check' during its initialization
is never read"

Fixes: f6d1973db2d2 ("drm/i915: Move modeset state verifier calls")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20170914162154.11304-1-colin.king@canonical.com

drivers/gpu/drm/i915/intel_display.c

@@ -12367,7 +12367,6 @@ static void intel_atomic_commit_tail(struct drm_atomic_state *state)
 	struct drm_crtc_state *old_crtc_state, *new_crtc_state;
 	struct drm_crtc *crtc;
 	struct intel_crtc_state *intel_cstate;
-	bool hw_check = intel_state->modeset;
 	u64 put_domains[I915_MAX_PIPES] = {};
 	unsigned crtc_vblank_mask = 0;
 	int i;
@@ -12384,7 +12383,6 @@ static void intel_atomic_commit_tail(struct drm_atomic_state *state)
 
 		if (needs_modeset(new_crtc_state) ||
 		    to_intel_crtc_state(new_crtc_state)->update_pipe) {
-			hw_check = true;
 
 			put_domains[to_intel_crtc(crtc)->pipe] =
 				modeset_get_crtc_power_domains(crtc,