usermodehelper: use UMH_WAIT_PROC consistently

usermodehelper: use UMH_WAIT_PROC consistently

BugLink: http://bugs.launchpad.net/bugs/963685

A few call_usermodehelper() callers use the hardcoded constant instead of
the proper UMH_WAIT_PROC, fix them.

Reported-by: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Lars Ellenberg <drbd-dev@lists.linbit.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Michal Januszewski <spock@gentoo.org>
Cc: Florian Tobias Schandinat <FlorianSchandinat@gmx.de>
Cc: Kentaro Takeda <takedakn@nttdata.co.jp>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: James Morris <jmorris@namei.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
(cherry picked from commit 70834d3070c3f3015ab5c05176d54bd4a0100546)

Signed-off-by: Tim Gardner <tim.gardner@canonical.com>