x86/ldt: Further fix FPU emulation

x86/ldt: Further fix FPU emulation

commit 12e244f4b550498bbaf654a52f93633f7dde2dc7 upstream.

The previous fix confused a selector with a segment prefix.  Fix it.

Compile-tested only.

Cc: Juergen Gross <jgross@suse.com>
Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Fixes: 4809146b86c3 ("x86/ldt: Correct FPU emulation access to LDT")
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>