Backout the process shielding of all but the boot cpu during boot.

This patch backs out the shield-procs-boot patch.

The process shielding during system boot causes init's and kernel daemon's
task->rt.nr_cpus_allowed to be set to a value of 1.

This subsequently causes user-space multithreaded RT scheduling class
applications, as well as RT scheduling class kernel daemons to execute
on only one cpu.

Since the process shielding during boot was only for getting luigi
to boot successfully, back out this patch.

Developed-by: John Blackwood <john.blackwood@ccur.com>
Index: b/init/main.c
===================================================================
--- a/init/main.c
+++ b/init/main.c
@@ -546,17 +546,6 @@ static void __init boot_cpu_init(void)
 	set_cpu_active(cpu, true);
 	set_cpu_present(cpu, true);
 	set_cpu_possible(cpu, true);
-#ifdef CONFIG_SHIELD
-	/* keep all but the boot cpu process shielded until
-	 * system_state == SYSTEM_RUNNING.
-	 */
-	bitmap_fill(cpumask_bits(&shielded_procs), NR_CPUS);
-	cpumask_clear_cpu(cpu, &shielded_procs);
-
-	bitmap_zero(cpumask_bits(&init_task.cpus_allowed_actual), NR_CPUS);
-	cpumask_set_cpu(cpu, &init_task.cpus_allowed_actual);
-	printk(KERN_INFO "Process shielded all but boot cpu during boot.\n");
-#endif
 }
 
 void __init __weak smp_setup_processor_id(void)
@@ -895,14 +884,6 @@ static noinline int init_post(void)
 	system_state = SYSTEM_RUNNING;
 	numa_default_policy();
 
-#ifdef CONFIG_SHIELD
-	/*
-	 * Recalculate every task's actual affinity, now that
-	 * the initial set of CPUs is officially online.
-	 */
-	set_shielded_procs(cpu_none_mask);
-	printk(KERN_INFO "Release early-boot process shielding\n");
-#endif
 
 	current->signal->flags |= SIGNAL_UNKILLABLE;
 
@@ -993,6 +974,14 @@ static int __init kernel_init(void * unu
 		prepare_namespace();
 	}
 
+#ifdef CONFIG_SHIELD
+	/*
+	 * Recalculate every task's actual affinity, now that
+	 * the initial set of CPUs is officially online.
+	 */
+	set_shielded_procs(cpu_none_mask);
+#endif
+
 	/*
 	 * Ok, we have completed the initial bootup, and
 	 * we're essentially up and running. Get rid of the