torture: Add timestamps to kvm-test-1-run-qemu.sh output

The kvm-test-1-run-qemu.sh script logs the torture-test start time and
also when it starts getting impatient for the test to finish.  However, it
does not timestamp these log messages, which can make debugging needlessly
challenging.  This commit therefore adds timestamps to these messages.

Signed-off-by: Paul E. McKenney <paulmck@kernel.org>