x86/asm/entry/64: Add missing CFI annotation

This is a missing bit of the recent MOV-to-PUSH conversion.

Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Alexei Starovoitov <ast@plumgrid.com>
Cc: Andy Lutomirski <luto@amacapital.net>
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: Steven Rostedt <rostedt@goodmis.org>
Cc: Will Drewry <wad@chromium.org>
Link: http://lkml.kernel.org/r/1427452582-21624-1-git-send-email-dvlasenk@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>

arch/x86/kernel/entry_64.S

@@ -248,6 +248,7 @@ GLOBAL(system_call_after_swapgs)
 	pushq_cfi_reg	r10			/* pt_regs->r10 */
 	pushq_cfi_reg	r11			/* pt_regs->r11 */
 	sub	$(6*8),%rsp /* pt_regs->bp,bx,r12-15 not saved */
+	CFI_ADJUST_CFA_OFFSET 6*8
 
 	testl $_TIF_WORK_SYSCALL_ENTRY, ASM_THREAD_INFO(TI_flags, %rsp, SIZEOF_PTREGS)
 	jnz tracesys