multiple-pipeline: reduce debug verbosity

Dumping all tasks even on a dedicated test system, running Ubuntu
generates too much output, which is difficult to find useful
information in. Dump waiting tasks and locks help instead to identify
kernel dead-locks.

Signed-off-by: Guennadi Liakhovetski <guennadi.liakhovetski@linux.intel.com>

Author: lyakh

test-case/multiple-pipeline.sh

@@ -207,7 +207,8 @@ do
     sleep 1 # try not to pollute the next iteration
 
     if pgrep arecord || pgrep aplay; then
-        printf '%c' 't' | sudo tee /proc/sysrq-trigger > /dev/null
+        printf 'd' | sudo tee /proc/sysrq-trigger > /dev/null
+        printf 'w' | sudo tee /proc/sysrq-trigger > /dev/null
         sleep 1
     fi