cpumask: remove dangerous CPU_MASK_ALL_PTR, &CPU_MASK_ALL

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 *).

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>
diff --git a/kernel/kmod.c b/kernel/kmod.c
index a27a5f6..f0c8f54 100644
--- a/kernel/kmod.c
+++ b/kernel/kmod.c
@@ -167,7 +167,7 @@
 	}
 
 	/* We can run anywhere, unlike our parent keventd(). */
-	set_cpus_allowed_ptr(current, CPU_MASK_ALL_PTR);
+	set_cpus_allowed_ptr(current, cpu_all_mask);
 
 	/*
 	 * Our parent is keventd, which runs with elevated scheduling priority.