rusage and ihklib: Fix out-of-memory reporting and cleanup

1. Fix OOM: Count memory usage only when allocation succeeded
2. Fix OOM: Make user allocation fail when memory is running out
3. Fix OOM: Move rusage_init() before numa_init()
4. Cleanup: Rename ihkconfig/ihkosctl functions
5. Cleanup: Pass event type to eventfd()
6. Cleanup: arch/.../rusage.h --> arch/.../arch_rusage.h

arch/x86/kernel/cpu.c

@@ -792,7 +792,7 @@ void init_cpu(void)
 	init_pat();
 }
 
-void setup_x86(void)
+void setup_x86_phase1(void)
 {
 	cpu_disable_interrupt();
 
@@ -801,7 +801,10 @@ void setup_x86(void)
 	init_gdt();
 
 	init_page_table();
+}
 
+void setup_x86_phase2(void)
+{
 	check_no_execute();
 
 	init_lapic_bsp();