locking/arch: Rename set_mb() to smp_store_mb()

Since set_mb() is really about an smp_mb() -- not a IO/DMA barrier
like mb() rename it to match the recent smp_load_acquire() and
smp_store_release().

Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
diff --git a/kernel/locking/qspinlock_paravirt.h b/kernel/locking/qspinlock_paravirt.h
index 27ab96d..04ab181 100644
--- a/kernel/locking/qspinlock_paravirt.h
+++ b/kernel/locking/qspinlock_paravirt.h
@@ -175,7 +175,7 @@
 		 *
 		 * Matches the xchg() from pv_kick_node().
 		 */
-		set_mb(pn->state, vcpu_halted);
+		smp_store_mb(pn->state, vcpu_halted);
 
 		if (!READ_ONCE(node->locked))
 			pv_wait(&pn->state, vcpu_halted);