powerpc/85xx: Remove stale BUG_ON in mpc85xx_smp_init

Under the FSL Hypervisor we triggered a BUG_ON in mpc85xx_smp_init that
expected smp_ops.message_pass to be explicity set.  However recent
changes allows smp_ops.message_pass to be NULL and handled by default
code.  Thus the BUG_ON isn't relevant anymore.
Signed-off-by: Laurentiu TUDOR <Laurentiu.Tudor@freescale.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>

arch/powerpc/platforms/85xx/smp.c

@@ -2,7 +2,7 @@
  * Author: Andy Fleming <afleming@freescale.com>
  * 	   Kumar Gala <galak@kernel.crashing.org>
  *
- * Copyright 2006-2008 Freescale Semiconductor Inc.
+ * Copyright 2006-2008, 2011 Freescale Semiconductor Inc.
  *
  * This program is free software; you can redistribute  it and/or modify it
  * under  the terms of  the GNU General  Public License as published by the
@@ -239,12 +239,13 @@ void __init mpc85xx_smp_init(void)
 	}
 
 	if (cpu_has_feature(CPU_FTR_DBELL)) {
-		/* .message_pass defaults to smp_muxed_ipi_message_pass */
+		/*
+		 * If left NULL, .message_pass defaults to
+		 * smp_muxed_ipi_message_pass
+		 */
 		smp_85xx_ops.cause_ipi = doorbell_cause_ipi;
 	}
 
-	BUG_ON(!smp_85xx_ops.message_pass);
-
 	smp_ops = &smp_85xx_ops;
 
 #ifdef CONFIG_KEXEC