s390: Remove BKL from prng

cycle_kernel_lock() was added during the big BKL pushdown. It should
ensure the serializiation against driver init code. In this case there
is nothing to serialize. Remove it.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
LKML-Reference: <20091010153349.601625576@linutronix.de>
Acked-by: Jan Glauber <jang@linux.vnet.ibm.com>

arch/s390/crypto/prng.c

@@ -6,7 +6,6 @@
 #include <linux/fs.h>
 #include <linux/init.h>
 #include <linux/kernel.h>
-#include <linux/smp_lock.h>
 #include <linux/miscdevice.h>
 #include <linux/module.h>
 #include <linux/moduleparam.h>
@@ -49,7 +48,6 @@ static unsigned char parm_block[32] = {
 
 static int prng_open(struct inode *inode, struct file *file)
 {
-	cycle_kernel_lock();
 	return nonseekable_open(inode, file);
 }