x86: fix ktermios-termio conversion

The legacy TCSETA{,W,F} ioctls failed to set the termio->c_line field
on x86. This adds a missing get_user.

The same ioctls also fail to report faulting user pointers, which
we keep ignoring.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>