unpack-trees: remove unneeded continue

The continue is the last statement in the loop, so not needed.
This situation arose in 700e66d66 (2010-07-30, unpack-trees: let
read-tree -u remove index entries outside sparse area) when statements
after the continue were removed.

Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

unpack-trees.c

@@ -253,7 +253,6 @@ static int check_updates(struct unpack_trees_options *o)
 			display_progress(progress, ++cnt);
 			if (o->update && !o->dry_run)
 				unlink_entry(ce);
-			continue;
 		}
 	}
 	remove_marked_cache_entries(index);