x86/asm/entry/64: Fix incorrect symbolic constant usage: R11->ARGOFFSET

Since the last fix of this nature, a few more instances have crept
in. Fix them up. No object code changes (constants have the same
value).

Signed-off-by: Denys Vlasenko <[e-mail]>
Signed-off-by: Andy Lutomirski <[e-mail]>
Cc: Alexei Starovoitov <[e-mail]>
Cc: Borislav Petkov <[e-mail]>
Cc: Frederic Weisbecker <[e-mail]>
Cc: H. Peter Anvin <[e-mail]>
Cc: Kees Cook <[e-mail]>
Cc: Linus Torvalds <[e-mail]>
Cc: Oleg Nesterov <[e-mail]>
Cc: Will Drewry <[e-mail]>
Link: http://lkml.kernel.org/r/[e-mail]
Link: http://lkml.kernel.org/r/[e-mail]
Signed-off-by: Ingo Molnar <[e-mail]>

arch/x86/kernel/entry_64.S

···
 	 * Try to use SYSRET instead of IRET if we're returning to
 	 * a completely clean 64-bit userspace context.
 	 */
-	movq (RCX-R11)(%rsp), %rcx
-	cmpq %rcx,(RIP-R11)(%rsp)		/* RCX == RIP */
+	movq (RCX-ARGOFFSET)(%rsp), %rcx
+	cmpq %rcx,(RIP-ARGOFFSET)(%rsp)		/* RCX == RIP */
 	jne opportunistic_sysret_failed
 
 	/*
···
 	shr $__VIRTUAL_MASK_SHIFT, %rcx
 	jnz opportunistic_sysret_failed
 
-	cmpq $__USER_CS,(CS-R11)(%rsp)		/* CS must match SYSRET */
+	cmpq $__USER_CS,(CS-ARGOFFSET)(%rsp)	/* CS must match SYSRET */
 	jne opportunistic_sysret_failed
 
 	movq (R11-ARGOFFSET)(%rsp), %r11