drm/gma500: Add some local 'fb' variables

Add a local 'fb' variable to a few places to get rid of the
'crtc->primary->fb' stuff. Looks neater and helps me with my poor
coccinelle skills later.

Cc: Patrik Jakobsson <patrik.r.jakobsson@gmail.com>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1479498793-31021-7-git-send-email-ville.syrjala@linux.intel.com
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/gma500/gma_display.c

@@ -59,7 +59,8 @@ int gma_pipe_set_base(struct drm_crtc *crtc, int x, int y,
 	struct drm_device *dev = crtc->dev;
 	struct drm_psb_private *dev_priv = dev->dev_private;
 	struct gma_crtc *gma_crtc = to_gma_crtc(crtc);
-	struct psb_framebuffer *psbfb = to_psb_fb(crtc->primary->fb);
+	struct drm_framebuffer *fb = crtc->primary->fb;
+	struct psb_framebuffer *psbfb = to_psb_fb(fb);
 	int pipe = gma_crtc->pipe;
 	const struct psb_offset *map = &dev_priv->regmap[pipe];
 	unsigned long start, offset;
@@ -70,7 +71,7 @@ int gma_pipe_set_base(struct drm_crtc *crtc, int x, int y,
 		return 0;
 
 	/* no fb bound */
-	if (!crtc->primary->fb) {
+	if (!fb) {
 		dev_err(dev->dev, "No FB bound\n");
 		goto gma_pipe_cleaner;
 	}
@@ -81,19 +82,19 @@ int gma_pipe_set_base(struct drm_crtc *crtc, int x, int y,
 	if (ret < 0)
 		goto gma_pipe_set_base_exit;
 	start = psbfb->gtt->offset;
-	offset = y * crtc->primary->fb->pitches[0] + x * (crtc->primary->fb->bits_per_pixel / 8);
+	offset = y * fb->pitches[0] + x * (fb->bits_per_pixel / 8);
 
-	REG_WRITE(map->stride, crtc->primary->fb->pitches[0]);
+	REG_WRITE(map->stride, fb->pitches[0]);
 
 	dspcntr = REG_READ(map->cntr);
 	dspcntr &= ~DISPPLANE_PIXFORMAT_MASK;
 
-	switch (crtc->primary->fb->bits_per_pixel) {
+	switch (fb->bits_per_pixel) {
 	case 8:
 		dspcntr |= DISPPLANE_8BPP;
 		break;
 	case 16:
-		if (crtc->primary->fb->depth == 15)
+		if (fb->depth == 15)
 			dspcntr |= DISPPLANE_15_16BPP;
 		else
 			dspcntr |= DISPPLANE_16BPP;