rcutorture: Remove unused script, config2frag.sh

The 'config2frag.sh' script is not used, so this commit removes it.

Fixes: c87b9c60 ("rcutorture: Add KVM-based test framework")

Signed-off-by: SeongJae Park <sj38.park@gmail.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>