drm/vc4: kms: Store channel in local variable

We use the channel from our vc4_crtc_state structure in multiple places,
let's store it in a local variable to make it cleaner.
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Acked-by: Thomas Zimmermann <tzimmermann@suse.de>
Link: https://lore.kernel.org/r/20220328153659.2382206-5-maxime@cerno.tech

drivers/gpu/drm/vc4/vc4_kms.c

@@ -283,13 +283,14 @@ static void vc5_hvs_pv_muxing_commit(struct vc4_dev *vc4,
 	for_each_new_crtc_in_state(state, crtc, crtc_state, i) {
 		struct vc4_crtc_state *vc4_state = to_vc4_crtc_state(crtc_state);
 		struct vc4_crtc *vc4_crtc = to_vc4_crtc(crtc);
+		unsigned int channel = vc4_state->assigned_channel;
 
 		if (!vc4_state->update_muxing)
 			continue;
 
 		switch (vc4_crtc->data->hvs_output) {
 		case 2:
-			mux = (vc4_state->assigned_channel == 2) ? 0 : 1;
+			mux = (channel == 2) ? 0 : 1;
 			reg = HVS_READ(SCALER_DISPECTRL);
 			HVS_WRITE(SCALER_DISPECTRL,
 				  (reg & ~SCALER_DISPECTRL_DSP2_MUX_MASK) |
@@ -297,10 +298,10 @@ static void vc5_hvs_pv_muxing_commit(struct vc4_dev *vc4,
 			break;
 
 		case 3:
-			if (vc4_state->assigned_channel == VC4_HVS_CHANNEL_DISABLED)
+			if (channel == VC4_HVS_CHANNEL_DISABLED)
 				mux = 3;
 			else
-				mux = vc4_state->assigned_channel;
+				mux = channel;
 
 			reg = HVS_READ(SCALER_DISPCTRL);
 			HVS_WRITE(SCALER_DISPCTRL,
@@ -309,10 +310,10 @@ static void vc5_hvs_pv_muxing_commit(struct vc4_dev *vc4,
 			break;
 
 		case 4:
-			if (vc4_state->assigned_channel == VC4_HVS_CHANNEL_DISABLED)
+			if (channel == VC4_HVS_CHANNEL_DISABLED)
 				mux = 3;
 			else
-				mux = vc4_state->assigned_channel;
+				mux = channel;
 
 			reg = HVS_READ(SCALER_DISPEOLN);
 			HVS_WRITE(SCALER_DISPEOLN,
@@ -322,10 +323,10 @@ static void vc5_hvs_pv_muxing_commit(struct vc4_dev *vc4,
 			break;
 
 		case 5:
-			if (vc4_state->assigned_channel == VC4_HVS_CHANNEL_DISABLED)
+			if (channel == VC4_HVS_CHANNEL_DISABLED)
 				mux = 3;
 			else
-				mux = vc4_state->assigned_channel;
+				mux = channel;
 
 			reg = HVS_READ(SCALER_DISPDITHER);
 			HVS_WRITE(SCALER_DISPDITHER,