torture: Fold parse-torture.sh into parse-console.sh

torture: Fold parse-torture.sh into parse-console.sh

The rcutorture scripting scans the console output twice, once to look
for various sorts of hangs and again to find warnings and panics.
Unfortunately, only the output of the second scan gets written to the
console.log.diags file, which can cause hangs to be overlooked.
This commit therefore folds the parse-torture.sh script (which looks
for hangs) into the parse-console.sh script (which looks for warnings
and panics).  This allows both types of failure information to be
added to console.log.diags, while still reliably removing this file
when it proves to be empty.

This also fixes a long-standing bug where rcuperf log files would
unconditionally complain about a hang.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Tested-by: Nicholas Piggin <npiggin@gmail.com>