tests/test-status-inprocess.py.out

check-code: allow command substitution with $(command)

Both `command` and $(command) are specified by POSIX. The latter nests
better. I don't see why we shouldn't allow both (or only the latter).

Differential Revision: https://phab.mercurial-scm.org/D6789

% creating repo
% add and commit
C test.py
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M test.py