x86/traps: Disable interrupts in exc_aligment_check()

exc_alignment_check() fails to disable interrupts before returning to the
entry code.

Fixes: ca4c6a98

 ("x86/traps: Make interrupt enable/disable symmetric in C code")
Reported-by:  <syzbot+0889df9502bc0f112b31@syzkaller.appspotmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Andy Lutomirski <luto@kernel.org>
Link: https://lkml.kernel.org/r/20200708192934.076519438@linutronix.de