Fix weird uses of num_online_cpus().

This may be OK in archs with contiguous CPU numbers and without
hotplug CPUs, but it sets a terrible example.

And open-coding it like drivers/scsi/hpsa.c is just weird.

BTRFS has a weird comparison with num_online_cpus() too, but since
BTRFS just screwed up my test machines' root partition, I'm not
touching it :)
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Reported-by: Oleg Drokin <green@linuxhacker.ru>

arch/m32r/kernel/smpboot.c

@@ -376,7 +376,7 @@ void __init smp_cpus_done(unsigned int max_cpus)
 	if (!cpumask_equal(&cpu_callin_map, cpu_online_mask))
 		BUG();
 
-	for (cpu_id = 0 ; cpu_id < num_online_cpus() ; cpu_id++)
+	for_each_online_cpu(cpu_id)
 		show_cpu_info(cpu_id);
 
 	/*

arch/sh/include/asm/mmu_context.h

@@ -99,7 +99,7 @@ static inline int init_new_context(struct task_struct *tsk,
 {
 	int i;
 
-	for (i = 0; i < num_online_cpus(); i++)
+	for_each_online_cpu(i)
 		cpu_context(i, mm) = NO_CONTEXT;
 
 	return 0;

arch/sh/kernel/smp.c

@@ -363,7 +363,7 @@ void flush_tlb_mm(struct mm_struct *mm)
 		smp_call_function(flush_tlb_mm_ipi, (void *)mm, 1);
 	} else {
 		int i;
-		for (i = 0; i < num_online_cpus(); i++)
+		for_each_online_cpu(i)
 			if (smp_processor_id() != i)
 				cpu_context(i, mm) = 0;
 	}
@@ -400,7 +400,7 @@ void flush_tlb_range(struct vm_area_struct *vma,
 		smp_call_function(flush_tlb_range_ipi, (void *)&fd, 1);
 	} else {
 		int i;
-		for (i = 0; i < num_online_cpus(); i++)
+		for_each_online_cpu(i)
 			if (smp_processor_id() != i)
 				cpu_context(i, mm) = 0;
 	}
@@ -443,7 +443,7 @@ void flush_tlb_page(struct vm_area_struct *vma, unsigned long page)
 		smp_call_function(flush_tlb_page_ipi, (void *)&fd, 1);
 	} else {
 		int i;
-		for (i = 0; i < num_online_cpus(); i++)
+		for_each_online_cpu(i)
 			if (smp_processor_id() != i)
 				cpu_context(i, vma->vm_mm) = 0;
 	}

arch/um/kernel/smp.c

@@ -45,7 +45,7 @@ void smp_send_stop(void)
 	int i;
 
 	printk(KERN_INFO "Stopping all CPUs...");
-	for (i = 0; i < num_online_cpus(); i++) {
+	for_each_online_cpu(i) {
 		if (i == current_thread->cpu)
 			continue;
 		os_write_file(cpu_data[i].ipi_pipe[1], "S", 1);

drivers/scsi/hpsa.c

@@ -6632,14 +6632,12 @@ static void fail_all_outstanding_cmds(struct ctlr_info *h)
 
 static void set_lockup_detected_for_all_cpus(struct ctlr_info *h, u32 value)
 {
-	int i, cpu;
+	int cpu;
 
-	cpu = cpumask_first(cpu_online_mask);
-	for (i = 0; i < num_online_cpus(); i++) {
+	for_each_online_cpu(cpu) {
 		u32 *lockup_detected;
 		lockup_detected = per_cpu_ptr(h->lockup_detected, cpu);
 		*lockup_detected = value;
-		cpu = cpumask_next(cpu, cpu_online_mask);
 	}
 	wmb(); /* be sure the per-cpu variables are out to memory */
 }