LU-4423 obd: use ktime_t for calculating elapsed time

LU-4423 obd: use ktime_t for calculating elapsed time

process_param2_config() tries to print how much time has passed
across a call_usermodehelper() function, and uses struct timeval
for that.

We want to remove this structure, so this is better expressed
in terms of ktime_t and ktime_us_delta().

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Change-Id: I90c61d9d49ee0d500772f1b370790e37859f18b2
Signed-off-by: Oleg Drokin <green@linuxhacker.ru>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: James Simmons <uja.ornl@yahoo.com>
Reviewed-on: https://review.whamcloud.com/23146
Tested-by: Jenkins
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Andreas Dilger <andreas.dilger@intel.com>
Reviewed-by: Dmitry Eremin <dmitry.eremin@intel.com>