#2 (Shellcheck) SC2017: Increase precision by replacing a/b*c with a*c/b.

Line 305:
  asize="$(((${fline%%[ ]*}+512)/1024*${math:?}))"
                                ^-- SC2017: Increase precision by replacing a/b*c with a*c/b.

Shellcheck prints the following warning. ``` Line 305: asize="$(((${fline%%[ ]*}+512)/1024*${math:?}))" ^-- SC2017: Increase precision by replacing a/b*c with a*c/b. ``` https://github.com/koalaman/shellcheck/wiki/SC2017 https://www.shellcheck.net/ This code does not necessarily require being precise, but it would be good to make it more precise anyways. The idea is that it should return a value in `MB` that is ~equivalent to the size of the `.wav` or `.au` files plus 100-200 MB to provide a safe cushion so that this script will not run out of space in `$TMP`. The problem is accounting for the size difference between the source files which could be a format such as `flac` and the output files which will likely be `wav`. If the source files are `wav` or`Sun/NeXT` audio files there will be no conversion and this does not need to be accounted for. Additionally it should not cause new shellcheck warnings and should be done with pure/portable shell.