Reinstate do_console if kernel not provided

Signed-off-by: Richard Henderson <rth@twiddle.net>
diff --git a/init.c b/init.c
index e7b506f..b53bab6 100644
--- a/init.c
+++ b/init.c
@@ -300,7 +300,7 @@
   pci_setup();
   vgahw_init();
 
-  swppal(kernel_entry, &pcb);
+  swppal(kernel_entry ? kernel_entry : do_console, &pcb);
 }
 
 void