cpumemlog: `$STR` picks up -t option

[stefanedwards]

If giving the -t option to cpumemlog, but not the optional string, the -t argument gets picked up as $2. Here are some examples, where the printed line is the resolved output filename.

$ ./cpumemlog 1
cpumemlog_1.txt

$ ./cpumemlog 1 lala
cpumemlog_1_lala.txt

$ ./cpumemlog 1 lala -t=5
cpumemlog_1_lala.txt

$ ./cpumemlog 1 -t=5
cpumemlog_1_-t=5.txt

This does not occur when specifying an output filename (with the -o option cf. my pull request #1).

It can be solved by updating the routine in lines 60-70 (##Get options) to work with positional arguments.