tests: remove crufty test=test_name code from old tests

tests: remove crufty test=test_name code from old tests

Before init.sh and similar, we would set test=test_name, and then
construct temporary file names using $test.  Now that each
init.sh-using test is in its own directory, that practice is unwelcome.
Remove bad examples.
* tests/rm/f-1: Per above.
* tests/rm/i-1: Likewise.
* tests/rm/interactive-always: Likewise.
* tests/rm/interactive-once: Likewise.
* tests/rm/ir-1: Likewise.
* tests/rm/r-1: Likewise.