locking/ww_mutex: Fix compilation of __WW_MUTEX_INITIALIZER

commit af2e859e upstream.

From conflicting macro parameters, passing the wrong name to
__MUTEX_INITIALIZER and a stray '\', #define __WW_MUTEX_INITIALIZER was
very unhappy.

One unnecessary change was to choose to pass &ww_class instead of
implicitly taking the address of the class within the macro.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Maarten Lankhorst <maarten.lankhorst@canonical.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Fixes: 1b375dc3 ("mutex: Move ww_mutex definitions to ww_mutex.h")
Link: http://lkml.kernel.org/r/20161201114711.28697-2-chris@chris-wilson.co.ukSigned-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

include/linux/ww_mutex.h

@@ -51,10 +51,10 @@ struct ww_mutex {
 };
 
 #ifdef CONFIG_DEBUG_LOCK_ALLOC
-# define __WW_CLASS_MUTEX_INITIALIZER(lockname, ww_class) \
-		, .ww_class = &ww_class
+# define __WW_CLASS_MUTEX_INITIALIZER(lockname, class) \
+		, .ww_class = class
 #else
-# define __WW_CLASS_MUTEX_INITIALIZER(lockname, ww_class)
+# define __WW_CLASS_MUTEX_INITIALIZER(lockname, class)
 #endif
 
 #define __WW_CLASS_INITIALIZER(ww_class) \
@@ -63,7 +63,7 @@ struct ww_mutex {
 		, .mutex_name = #ww_class "_mutex" }
 
 #define __WW_MUTEX_INITIALIZER(lockname, class) \
-		{ .base = { \__MUTEX_INITIALIZER(lockname) } \
+		{ .base =  __MUTEX_INITIALIZER(lockname.base) \
 		__WW_CLASS_MUTEX_INITIALIZER(lockname, class) }
 
 #define DEFINE_WW_CLASS(classname) \