workqueue: Fix flag collision

BugLink: http://bugs.launchpad.net/bugs/1718195

commit fbf1c41f upstream.

Commit 0a94efb5 ("workqueue: implicit ordered attribute should be
overridable") introduced a __WQ_ORDERED_EXPLICIT flag but gave it the
same value as __WQ_LEGACY.  I don't believe these were intended to
mean the same thing, so renumber __WQ_ORDERED_EXPLICIT.

Fixes: 0a94efb5 ("workqueue: implicit ordered attribute should be ...")
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>

include/linux/workqueue.h

@@ -311,7 +311,7 @@ enum {
 
 	__WQ_DRAINING		= 1 << 16, /* internal: workqueue is draining */
 	__WQ_ORDERED		= 1 << 17, /* internal: workqueue is ordered */
-	__WQ_ORDERED_EXPLICIT	= 1 << 18, /* internal: alloc_ordered_workqueue() */
+	__WQ_ORDERED_EXPLICIT	= 1 << 19, /* internal: alloc_ordered_workqueue() */
 
 	WQ_MAX_ACTIVE		= 512,	  /* I like 512, better ideas? */
 	WQ_MAX_UNBOUND_PER_CPU	= 4,	  /* 4 * #cpus for unbound wq */