dump: Remove extra leading dashes from dump suffixes.

ir/be/bepbqpcoloring.c

@@ -598,7 +598,7 @@ static void be_pbqp_coloring(be_chordal_env_t *env)
 	/* dump graph after inserting perms */
 	if (env->opts->dump_flags & BE_CH_DUMP_CONSTR) {
 		char buf[256];
-		snprintf(buf, sizeof(buf), "-%s-constr", cls->name);
+		snprintf(buf, sizeof(buf), "%s-constr", cls->name);
 		dump_ir_graph(irg, buf);
 	}
 

ir/stat/dags.c

@@ -393,7 +393,7 @@ void count_dags_in_graph(graph_entry_t *global, graph_entry_t *graph)
 	/* dump for test */
 	mark_options = root_env.options;
 	set_dump_node_vcgattr_hook(stat_dag_mark_hook);
-	dump_ir_graph(graph->irg, "-dag");
+	dump_ir_graph(graph->irg, "dag");
 	set_dump_node_vcgattr_hook(NULL);
 
 	assert(id == root_env.num_of_dags);