drm/amd/display: Drop unnecessary function call

After refactor our amdgpu_dm_atomic_commit, this function only invoke
drm_atomic_helper_commit. For this reason, this commit drops
amdgpu_dm_atomic_commit and add drm_atomic_helper_commit directly in the
atomic_commit hook.

v2: squash in warning fix (Alex)
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Rodrigo Siqueira <Rodrigo.Siqueira@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c

@@ -196,10 +196,6 @@ static int amdgpu_dm_encoder_init(struct drm_device *dev,
 
 static int amdgpu_dm_connector_get_modes(struct drm_connector *connector);
 
-static int amdgpu_dm_atomic_commit(struct drm_device *dev,
-				   struct drm_atomic_state *state,
-				   bool nonblock);
-
 static void amdgpu_dm_atomic_commit_tail(struct drm_atomic_state *state);
 
 static int amdgpu_dm_atomic_check(struct drm_device *dev,
@@ -2212,7 +2208,7 @@ static const struct drm_mode_config_funcs amdgpu_dm_mode_funcs = {
 	.get_format_info = amd_get_format_info,
 	.output_poll_changed = drm_fb_helper_output_poll_changed,
 	.atomic_check = amdgpu_dm_atomic_check,
-	.atomic_commit = amdgpu_dm_atomic_commit,
+	.atomic_commit = drm_atomic_helper_commit,
 };
 
 static struct drm_mode_config_helper_funcs amdgpu_dm_mode_config_helperfuncs = {
@@ -8070,20 +8066,6 @@ static void amdgpu_dm_crtc_copy_transient_flags(struct drm_crtc_state *crtc_stat
 	stream_state->mode_changed = drm_atomic_crtc_needs_modeset(crtc_state);
 }
 
-static int amdgpu_dm_atomic_commit(struct drm_device *dev,
-				   struct drm_atomic_state *state,
-				   bool nonblock)
-{
-	/*
-	 * Add check here for SoC's that support hardware cursor plane, to
-	 * unset legacy_cursor_update
-	 */
-
-	return drm_atomic_helper_commit(dev, state, nonblock);
-
-	/*TODO Handle EINTR, reenable IRQ*/
-}
-
 /**
  * amdgpu_dm_atomic_commit_tail() - AMDgpu DM's commit tail implementation.
  * @state: The atomic state to commit