drm/amd/display: Simplify bool conversion

Fix the following coccicheck warning:
./drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c:8142:16-21: WARNING:
conversion to bool not needed here
Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Signed-off-by: Yang Li <yang.lee@linux.alibaba.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

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

@@ -8260,8 +8260,7 @@ static void amdgpu_dm_atomic_commit_tail(struct drm_atomic_state *state)
 			hdcp_update_display(
 				adev->dm.hdcp_workqueue, aconnector->dc_link->link_index, aconnector,
 				new_con_state->hdcp_content_type,
-				new_con_state->content_protection == DRM_MODE_CONTENT_PROTECTION_DESIRED ? true
-													 : false);
+				new_con_state->content_protection == DRM_MODE_CONTENT_PROTECTION_DESIRED);
 	}
 #endif