x86/asm/entry: Rename 'INIT_TSS_IST' to 'CPU_TSS_IST'

This has nothing to do with the init thread or the initial
anything. It's just the CPU's TSS.
Signed-off-by: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/a0bd5e26b32a2e1f08ff99017d0997118fbb2485.1425611534.git.luto@amacapital.netSigned-off-by: Ingo Molnar <mingo@kernel.org>

arch/x86/kernel/entry_64.S

@@ -959,7 +959,7 @@ apicinterrupt IRQ_WORK_VECTOR \
 /*
  * Exception entry points.
  */
-#define INIT_TSS_IST(x) PER_CPU_VAR(cpu_tss) + (TSS_ist + ((x) - 1) * 8)
+#define CPU_TSS_IST(x) PER_CPU_VAR(cpu_tss) + (TSS_ist + ((x) - 1) * 8)
 
 .macro idtentry sym do_sym has_error_code:req paranoid=0 shift_ist=-1
 ENTRY(\sym)
@@ -1015,13 +1015,13 @@ ENTRY(\sym)
 	.endif
 
 	.if \shift_ist != -1
-	subq $EXCEPTION_STKSZ, INIT_TSS_IST(\shift_ist)
+	subq $EXCEPTION_STKSZ, CPU_TSS_IST(\shift_ist)
 	.endif
 
 	call \do_sym
 
 	.if \shift_ist != -1
-	addq $EXCEPTION_STKSZ, INIT_TSS_IST(\shift_ist)
+	addq $EXCEPTION_STKSZ, CPU_TSS_IST(\shift_ist)
 	.endif
 
 	/* these procedures expect "no swapgs" flag in ebx */