parisc: Don't call faulthandler_disabled() in do_page_fault()

parisc: Don't call faulthandler_disabled() in do_page_fault()

It is dangerous to call faulthandler_disabled() when user_mode(regs)
is true.  The task pagefault_disabled counter is racy and it is not
updated atomically on parisc. As a result, calling faulthandler_disabled()
may cause erroneous termination.

We now handle execption fixups and termination when user_mode(regs) is
false in handle_interruption(). Thus, we can just remove the
faulthandler_disabled() check from do_page_fault().

Signed-off-by: John David Anglin <dave.anglin@bell.net>
Signed-off-by: Helge Deller <deller@gmx.de>