Add kprobe_fault_handler() to fix compilation for PA-RISC.
On PA-RISC we actually don't need that function as the recovery counter
is restored after interrupt. See the PA-RISC 2.0 Architecture Manual,
pg. 4-8, Figure 4-4: "Interruption Processing".

Fixes: b98cca44 ("mm, kprobes: generalize and rename notify_page_fault() as kprobe_page_fault()")
Signed-off-by: Sven Schnelle <svens@stackframe.org>
Signed-off-by: Helge Deller <deller@gmx.de>