rcutorture: Drop redundant "insoftirq" parameters

rcutorture: Drop redundant "insoftirq" parameters

Given that the rcutorture_one_extend_check() function now uses
in_serving_softirq() and in_hardirq(), it is no longer necessary to pass
insoftirq flags down the function-call stack.  This commit therefore
removes those flags, and, while in the area, does a bit of whitespace
cleanup.

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