merge-recursive: Do not look at working tree during a virtual ancestor merge

Fix another instance of a recursive merge incorrectly paying attention to
the working tree file during a virtual ancestor merge, that resulted in
spurious and useless "addinfo_cache failed" error message.

Signed-off-by: Junio C Hamano <gitster@pobox.com>

merge-recursive.c

@@ -1627,7 +1627,7 @@ static int merge_content(struct merge_options *o,
 		path_renamed_outside_HEAD = !path2 || !strcmp(path, path2);
 		if (!path_renamed_outside_HEAD) {
 			add_cacheinfo(mfi.mode, mfi.sha, path,
-				      0 /*stage*/, 1 /*refresh*/, 0 /*options*/);
+				      0, (!o->call_depth), 0);
 			return mfi.clean;
 		}
 	} else