A single case of using __get_cpu_var for address calculation.

Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Christoph Lameter <cl@linux.com>

Index: linux/drivers/char/random.c
===================================================================
--- linux.orig/drivers/char/random.c	2014-05-21 22:47:16.376070081 -0500
+++ linux/drivers/char/random.c	2014-05-21 22:47:16.368070243 -0500
@@ -838,7 +838,7 @@
 void add_interrupt_randomness(int irq, int irq_flags)
 {
 	struct entropy_store	*r;
-	struct fast_pool	*fast_pool = &__get_cpu_var(irq_randomness);
+	struct fast_pool	*fast_pool = this_cpu_ptr(&irq_randomness);
 	struct pt_regs		*regs = get_irq_regs();
 	unsigned long		now = jiffies;
 	cycles_t		cycles = random_get_entropy();