powerpc: fix compile error with 85xx/p1010rdb.c

Current linux-next compiled with mpc85xx_defconfig causes this:

arch/powerpc/platforms/85xx/p1010rdb.c:41:14: error: 'np' undeclared (first use in this function)
arch/powerpc/platforms/85xx/p1023_rds.c:102:14: error: 'np' undeclared (first use in this function)

Introduced in:
  commit 996983b7
  Author: Kyle Moffett <Kyle.D.Moffett@boeing.com>
  Date:   Fri Dec 2 06:28:02 2011 +0000
  powerpc/mpic: Search for open-pic device-tree node if NULL
Signed-off-by: Tony Breeds <tony@bakeyournoodle.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>

arch/powerpc/platforms/85xx/p1010rdb.c

@@ -38,10 +38,8 @@ void __init p1010_rdb_pic_init(void)
 	  0, 256, " OpenPIC  ");
 
 	BUG_ON(mpic == NULL);
-	of_node_put(np);
 
 	mpic_init(mpic);
-
 }