x86-64: Move irqcount from PDA to per-cpu.

tj: s/irqcount/irq_count/

Signed-off-by: Brian Gerst <brgerst@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
diff --git a/arch/x86/include/asm/pda.h b/arch/x86/include/asm/pda.h
index ae23deb..4527d70 100644
--- a/arch/x86/include/asm/pda.h
+++ b/arch/x86/include/asm/pda.h
@@ -15,7 +15,7 @@
 	unsigned long unused2;
 	unsigned long unused3;
 	unsigned long unused4;
-	int irqcount;			/* 32 Irq nesting counter. Starts -1 */
+	int unused5;
 	unsigned int unused6;		/* 36 was cpunumber */
 #ifdef CONFIG_CC_STACKPROTECTOR
 	unsigned long stack_canary;	/* 40 stack canary value */