drm/atmel-hlcdc: Use swap() where appropriate

@swap@
identifier TEMP;
expression A,B;
@@
- TEMP = A;
- A = B;
- B = TEMP;
+ swap(A, B);

@@
type T;
identifier swap.TEMP;
@@
(
- T TEMP;
|
- T TEMP = {...};
)
... when != TEMP

Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Boris Brezillon <bbrezillon@kernel.org>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20191010131159.17346-3-ville.syrjala@linux.intel.com
Reviewed-by: Boris Brezillon <boris.brezillon@collabora.com>

drivers/gpu/drm/atmel-hlcdc/atmel_hlcdc_plane.c

@@ -601,7 +601,6 @@ static int atmel_hlcdc_plane_atomic_check(struct drm_plane *p,
 	struct drm_framebuffer *fb = state->base.fb;
 	const struct drm_display_mode *mode;
 	struct drm_crtc_state *crtc_state;
-	unsigned int tmp;
 	int ret;
 	int i;
 
@@ -694,9 +693,7 @@ static int atmel_hlcdc_plane_atomic_check(struct drm_plane *p,
 	 * Swap width and size in case of 90 or 270 degrees rotation
 	 */
 	if (drm_rotation_90_or_270(state->base.rotation)) {
-		tmp = state->src_w;
-		state->src_w = state->src_h;
-		state->src_h = tmp;
+		swap(state->src_w, state->src_h);
 	}
 
 	if (!desc->layout.size &&