x86/spinlocks: Eliminate TICKET_MASK

The definition of it being questionable already (unnecessarily
including a cast), and it being used in a single place that can
be written shorter without it, remove this #define.

Along the same lines, simplify __ticket_spin_is_locked()'s main
expression, which was the more convoluted way because of needs
that went away with the recent type changes by Jeremy.

This is pure cleanup, no functional change intended.

Signed-off-by: Jan Beulich <[e-mail]>
Acked-by: Jeremy Fitzhardinge <[e-mail]>
Cc: Linus Torvalds <[e-mail]>
Cc: Andrew Morton <[e-mail]>
Cc: Peter Zijlstra <[e-mail]>
Link: http://lkml.kernel.org/r/[e-mail]
Signed-off-by: Ingo Molnar <[e-mail]>

arch/x86/include/asm/spinlock.h

···
 {
 	struct __raw_tickets tmp = ACCESS_ONCE(lock->tickets);
 
-	return !!(tmp.tail ^ tmp.head);
+	return tmp.tail != tmp.head;
 }
 
 static inline int __ticket_spin_is_contended(arch_spinlock_t *lock)
 {
 	struct __raw_tickets tmp = ACCESS_ONCE(lock->tickets);
 
-	return ((tmp.tail - tmp.head) & TICKET_MASK) > 1;
+	return (__ticket_t)(tmp.tail - tmp.head) > 1;
 }
 
 #ifndef CONFIG_PARAVIRT_SPINLOCKS

arch/x86/include/asm/spinlock_types.h

···
 #endif
 
 #define TICKET_SHIFT	(sizeof(__ticket_t) * 8)
-#define TICKET_MASK	((__ticket_t)((1 << TICKET_SHIFT) - 1))
 
 typedef struct arch_spinlock {
 	union {