Sync OpenBSD patchset 1081:

Only find each window once no matter how many panes, from Jonathan
Daugherty.

cmd-find-window.c

@@ -142,6 +142,7 @@ cmd_find_window_exec(struct cmd *self, struct cmd_ctx *ctx)
 
 			ARRAY_ADD(&list_idx, wm->idx);
 			ARRAY_ADD(&list_ctx, sctx);
+			break;
 		}
 	}
 	xfree(searchstr);