Test result filenames should use leading zeros when running multiple iterations

[grdumas]

Problem

When running multiple iterations (10 or greater) of CoreMark-PRO the test result files are do not contain any leading zeros, which leads to the files being sorted non-numerically. Because the number of iterations is specified when the test begins, I think the wrapper code could be modified to determine how many, if any, leading zeros would be needed.

Current behavior

After running 100 iterations the following result files were created:

coremark_pro_run_1
coremark_pro_run_10
coremark_pro_run_100
coremark_pro_run_11
coremark_pro_run_12
coremark_pro_run_13
coremark_pro_run_14
coremark_pro_run_15
coremark_pro_run_16
coremark_pro_run_17
coremark_pro_run_18
coremark_pro_run_19
coremark_pro_run_2
...

Desired behavior

With the requested changes implemented, the above files would look like:

coremark_pro_run_001
coremark_pro_run_002
...
coremark_pro_run_010
coremark_pro_run_011
coremark_pro_run_012
coremark_pro_run_013
coremark_pro_run_014
coremark_pro_run_015
coremark_pro_run_016
coremark_pro_run_017
coremark_pro_run_018
coremark_pro_run_019
...
coremark_pro_run_100

While if a smaller number of iterations were run, say 12, the resulting files would look like:

coremark_pro_run_01
coremark_pro_run_02
coremark_pro_run_03
...
coremark_pro_run_12

If fewer than 10 runs, no leading zeros would be added:

coremark_pro_run_1
coremark_pro_run_2
coremark_pro_run_3
...
coremark_pro_run_9

[dvalinrh]

This applies across all the wrappers.