cpumask: use zalloc_cpumask_var() where possible

Remove open-coded zalloc_cpumask_var() and zalloc_cpumask_var_node().

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
diff --git a/drivers/acpi/processor_perflib.c b/drivers/acpi/processor_perflib.c
index 11088cf..8ba0ed0 100644
--- a/drivers/acpi/processor_perflib.c
+++ b/drivers/acpi/processor_perflib.c
@@ -511,7 +511,7 @@
 	struct acpi_processor *match_pr;
 	struct acpi_psd_package *match_pdomain;
 
-	if (!alloc_cpumask_var(&covered_cpus, GFP_KERNEL))
+	if (!zalloc_cpumask_var(&covered_cpus, GFP_KERNEL))
 		return -ENOMEM;
 
 	mutex_lock(&performance_mutex);
@@ -558,7 +558,6 @@
 	 * Now that we have _PSD data from all CPUs, lets setup P-state 
 	 * domain info.
 	 */
-	cpumask_clear(covered_cpus);
 	for_each_possible_cpu(i) {
 		pr = per_cpu(processors, i);
 		if (!pr)
diff --git a/drivers/acpi/processor_throttling.c b/drivers/acpi/processor_throttling.c
index ce7cf3b..4c6c14c 100644
--- a/drivers/acpi/processor_throttling.c
+++ b/drivers/acpi/processor_throttling.c
@@ -77,7 +77,7 @@
 	struct acpi_tsd_package *pdomain, *match_pdomain;
 	struct acpi_processor_throttling *pthrottling, *match_pthrottling;
 
-	if (!alloc_cpumask_var(&covered_cpus, GFP_KERNEL))
+	if (!zalloc_cpumask_var(&covered_cpus, GFP_KERNEL))
 		return -ENOMEM;
 
 	/*
@@ -105,7 +105,6 @@
 	if (retval)
 		goto err_ret;
 
-	cpumask_clear(covered_cpus);
 	for_each_possible_cpu(i) {
 		pr = per_cpu(processors, i);
 		if (!pr)
diff --git a/drivers/net/sfc/efx.c b/drivers/net/sfc/efx.c
index 07a7e4b..cc4b2f9 100644
--- a/drivers/net/sfc/efx.c
+++ b/drivers/net/sfc/efx.c
@@ -884,13 +884,12 @@
 	int count;
 	int cpu;
 
-	if (unlikely(!alloc_cpumask_var(&core_mask, GFP_KERNEL))) {
+	if (unlikely(!zalloc_cpumask_var(&core_mask, GFP_KERNEL))) {
 		printk(KERN_WARNING
 		       "sfc: RSS disabled due to allocation failure\n");
 		return 1;
 	}
 
-	cpumask_clear(core_mask);
 	count = 0;
 	for_each_online_cpu(cpu) {
 		if (!cpumask_test_cpu(cpu, core_mask)) {
diff --git a/drivers/oprofile/buffer_sync.c b/drivers/oprofile/buffer_sync.c
index 8574622..c9e2ae9 100644
--- a/drivers/oprofile/buffer_sync.c
+++ b/drivers/oprofile/buffer_sync.c
@@ -154,9 +154,8 @@
 {
 	int err;
 
-	if (!alloc_cpumask_var(&marked_cpus, GFP_KERNEL))
+	if (!zalloc_cpumask_var(&marked_cpus, GFP_KERNEL))
 		return -ENOMEM;
-	cpumask_clear(marked_cpus);
 
 	start_cpu_work();