Fix another x86 sys/ucontext.h namespace issue (bug 21457)

[Joseph Myers]

This patch fixes a namespace issue for one more field in the x86
sys/ucontext.h that I missed in my previous changes.

Tested for x86_64.

2017-06-16  Joseph Myers  <joseph@codesourcery.com>

	[BZ #21457]
	* sysdeps/unix/sysv/linux/x86/sys/ucontext.h [__x86_64__] (struct
	_libc_xmmreg): Use __ctx in defining field.

diff --git a/sysdeps/unix/sysv/linux/x86/sys/ucontext.h b/sysdeps/unix/sysv/linux/x86/sys/ucontext.h
index 5fd64bf..0cbed08 100644
--- a/sysdeps/unix/sysv/linux/x86/sys/ucontext.h
+++ b/sysdeps/unix/sysv/linux/x86/sys/ucontext.h
@@ -107,7 +107,7 @@ struct _libc_fpxreg
 
 struct _libc_xmmreg
 {
-  __uint32_t	element[4];
+  __uint32_t	__ctx(element)[4];
 };
 
 struct _libc_fpstate

-- 
Joseph S. Myers
joseph@codesourcery.com