parisc: sync compat getdents

Add VERIFY_WRITE check in the beginning like compat_sys_getdents() EFAULT on
parisc if put_user() fails.

Signed-off-by: Alexandr Andreev <aandreev@openvz.org>
Signed-off-by: Alexey Dobriyan <adobriyan@openvz.org>
Cc: Kyle McMartin <kyle@mcmartin.ca>
Cc: Matthew Wilcox <willy@debian.org>
Cc: Grant Grundler <grundler@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Kyle McMartin <kyle@parisc-linux.org>