sh: fix unaligned and nonexistent address handling

unaligned and nonexistent address causes wrong exception
handling in traps_32.c(handle_unaligned_access).

'handle_unalinged_ins' should return -EFAULT if address error
is fixed up with kernel exception table, otherwise
'handle_unaligned_access' increases already fixed program counter
and then crash.

for example
   ioctl(fd, TCGETA, (struct termio *)-1)
never return and stay in TASK_UNINTERRUPTIBLE state forever
in my kernel.

Signed-off-by: SUGIOKA Toshinobu <sugioka@itonet.co.jp>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>