cpumask: remove dangerous CPU_MASK_ALL_PTR, &CPU_MASK_ALL.: x86

Impact: cleanup

(Thanks to Al Viro for reminding me of this, via Ingo)

CPU_MASK_ALL is the (deprecated) "all bits set" cpumask, defined as so:

	#define CPU_MASK_ALL (cpumask_t) { { ... } }

Taking the address of such a temporary is questionable at best,
unfortunately 321a8e9d (cpumask: add CPU_MASK_ALL_PTR macro) added
CPU_MASK_ALL_PTR:

	#define CPU_MASK_ALL_PTR (&CPU_MASK_ALL)

Which formalizes this practice.  One day gcc could bite us over this
usage (though we seem to have gotten away with it so far).

So replace everywhere which used &CPU_MASK_ALL or CPU_MASK_ALL_PTR
with the modern "cpu_all_mask" (a real const struct cpumask *), and remove
CPU_MASK_ALL_PTR altogether.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Acked-by: Ingo Molnar <mingo@elte.hu>
Reported-by: Al Viro <viro@zeniv.linux.org.uk>
Cc: Mike Travis <travis@sgi.com>

arch/x86/kernel/apic/es7000_32.c

@@ -457,7 +457,7 @@ static int es7000_apic_id_registered(void)
 
 static const cpumask_t *target_cpus_cluster(void)
 {
-	return &CPU_MASK_ALL;
+	return cpu_all_mask;
 }
 
 static const cpumask_t *es7000_target_cpus(void)

arch/x86/kernel/apic/numaq_32.c

@@ -336,7 +336,7 @@ static inline void numaq_smp_callin_clear_local_apic(void)
 
 static inline const cpumask_t *numaq_target_cpus(void)
 {
-	return &CPU_MASK_ALL;
+	return cpu_all_mask;
 }
 
 static inline unsigned long