netlink: Allow direct reclaim for fallback allocation

The backport of d35c99ff ("netlink: do not enter direct reclaim from
netlink_dump()") to the 4.4 branch (first in 4.4.32) mistakenly removed
direct claim from the initial large allocation _and_ the fallback
allocation which means that allocations can spuriously fail.
Fix the issue by adding back the direct reclaim flag to the fallback
allocation.

Fixes: 6d123f1d ("netlink: do not enter direct reclaim from netlink_dump()")
Signed-off-by: Ross Lagerwall <ross.lagerwall@citrix.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>