shell: Fix activate logic on surface map.

It should activate the newly mapped surface if not locked.
diff --git a/desktop-shell/shell.c b/desktop-shell/shell.c
index de54e37..05d7814 100644
--- a/desktop-shell/shell.c
+++ b/desktop-shell/shell.c
@@ -4860,7 +4860,7 @@
 		if (shsurf->state.relative &&
 		    shsurf->transient.flags == WL_SHELL_SURFACE_TRANSIENT_INACTIVE)
 			break;
-		if (!shell->locked)
+		if (shell->locked)
 			break;
 		wl_list_for_each(seat, &compositor->seat_list, link)
 			activate(shell, shsurf->surface, seat);