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 <dvlasenk@redhat.com>
Signed-off-by: Andy Lutomirski <luto@amacapital.net>
Cc: Alexei Starovoitov <ast@plumgrid.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Will Drewry <wad@chromium.org>
Link: http://lkml.kernel.org/r/1423778052-21038-1-git-send-email-dvlasenk@redhat.com
Link: http://lkml.kernel.org/r/f5e1c4084319a42e5f14d41e2d638949ce66bc08.1424989793.git.luto@amacapital.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>

arch/x86/kernel/entry_64.S

@@ -757,8 +757,8 @@ retint_swapgs:		/* return to user-space */
 	 * 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
 
 	/*
@@ -779,7 +779,7 @@ retint_swapgs:		/* return to user-space */
 	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