cpumask: define cleanup function for cpumasks

Now we can simplify code that allocates cpumasks for local needs.
Signed-off-by: Yury Norov <yury.norov@gmail.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

include/linux/cpumask.h

@@ -7,6 +7,7 @@
  * set of CPUs in a system, one bit position per CPU number.  In general,
  * only nr_cpu_ids (<= NR_CPUS) bits are valid.
  */
+#include <linux/cleanup.h>
 #include <linux/kernel.h>
 #include <linux/threads.h>
 #include <linux/bitmap.h>
@@ -990,6 +991,8 @@ static inline bool cpumask_available(cpumask_var_t mask)
 }
 #endif /* CONFIG_CPUMASK_OFFSTACK */
 
+DEFINE_FREE(free_cpumask_var, struct cpumask *, if (_T) free_cpumask_var(_T));
+
 /* It's common to want to use cpu_all_mask in struct member initializers,
  * so it has to refer to an address rather than a pointer. */
 extern const DECLARE_BITMAP(cpu_all_bits, NR_CPUS);