Detect an error case and prevent printing an uninitialized variable

pm_process_usage can return an error, and leave procs[i]->usage
unitialized.  Detect the error case and print a warning.  Also
make the initialization of procs[i]->usage to 0 unconditional,
so nothing will be printed in the final procrank stats when an
error is detected.

Change-Id: I03f90ae6a5ebb201b6e9e43593cec225e1a8ded0
1 file changed