rcutorture: Complain if an ->up_read() is delayed more than 10 seconds

rcutorture: Complain if an ->up_read() is delayed more than 10 seconds

The down/up SRCU reader testing uses an hrtimer handler to exit the SRCU
read-side critical section.  This might be delayed, and if delayed for
too long, it can prevent the rcutorture run from completing.  This commit
therefore complains if the hrtimer handler is delayed for more than
ten seconds.

[ paulmck, joel: Apply kernel test robot feedback to avoid
false-positive complaint of excessive ->up_read() delays by using
HRTIMER_MODE_HARD ]

Tested-by: kernel test robot <oliver.sang@intel.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Joel Fernandes <joelagnelf@nvidia.com>
Signed-off-by: Neeraj Upadhyay (AMD) <neeraj.upadhyay@kernel.org>