x86: clean up declarations and variables

Impact: cleanup, no code changed

 - syscalls.h       update declarations due to unifications
 - irq.c            declare smp_generic_interrupt() before it gets used
 - process.c        declare sys_fork() and sys_vfork() before they get used
 - tsc.c            rename tsc_khz shadowed variable
 - apic/probe_32.c  declare apic_default before it gets used
 - apic/nmi.c       prev_nmi_count should be unsigned
 - apic/io_apic.c   declare smp_irq_move_cleanup_interrupt() before it gets used
 - mm/init.c        declare direct_gbpages and free_initrd_mem before they get used

Signed-off-by: Jaswinder Singh Rajput <jaswinder@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/arch/x86/kernel/tsc.c b/arch/x86/kernel/tsc.c
index 7a567eb..a8dc0d0 100644
--- a/arch/x86/kernel/tsc.c
+++ b/arch/x86/kernel/tsc.c
@@ -384,13 +384,13 @@
 {
 	u64 tsc1, tsc2, delta, ref1, ref2;
 	unsigned long tsc_pit_min = ULONG_MAX, tsc_ref_min = ULONG_MAX;
-	unsigned long flags, latch, ms, fast_calibrate, tsc_khz;
+	unsigned long flags, latch, ms, fast_calibrate, hv_tsc_khz;
 	int hpet = is_hpet_enabled(), i, loopmin;
 
-	tsc_khz = get_hypervisor_tsc_freq();
-	if (tsc_khz) {
+	hv_tsc_khz = get_hypervisor_tsc_freq();
+	if (hv_tsc_khz) {
 		printk(KERN_INFO "TSC: Frequency read from the hypervisor\n");
-		return tsc_khz;
+		return hv_tsc_khz;
 	}
 
 	local_irq_save(flags);