drm/amd/display: Stop amdgpu_dm initialize when link nums greater than max_links

[Why]
Coverity report OVERRUN warning. There are
only max_links elements within dc->links. link
count could up to AMDGPU_DM_MAX_DISPLAY_INDEX 31.

[How]
Make sure link count less than max_links.
Reviewed-by: Harry Wentland <harry.wentland@amd.com>
Acked-by: Tom Chung <chiahsuan.chung@amd.com>
Signed-off-by: Hersen Wu <hersenxs.wu@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

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

@@ -4689,17 +4689,17 @@ static int amdgpu_dm_initialize_drm_device(struct amdgpu_device *adev)
 		}
 	}
 
-	/* loops over all connectors on the board */
-	for (i = 0; i < link_cnt; i++) {
-		struct dc_link *link = NULL;
-
-		if (i > AMDGPU_DM_MAX_DISPLAY_INDEX) {
+	if (link_cnt > MAX_LINKS) {
 		DRM_ERROR(
 			"KMS: Cannot support more than %d display indexes\n",
-					AMDGPU_DM_MAX_DISPLAY_INDEX);
-			continue;
+				MAX_LINKS);
+		goto fail;
 	}
 
+	/* loops over all connectors on the board */
+	for (i = 0; i < link_cnt; i++) {
+		struct dc_link *link = NULL;
+
 		link = dc_get_link_at_index(dm->dc, i);
 
 		if (link->connector_signal == SIGNAL_TYPE_VIRTUAL) {