test: remove common.fail()

common.fail() was added to paste over issues with assert.fail() function
signature. assert.fail() has been updated to accept a single argument so
common.fail() is no longer necessary.

PR-URL: https://github.com/nodejs/node/pull/12293


Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Michaël Zasso <targos@protonmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>