Revert "hush: fix segfault on syntax error"

128059b9 ("hush: fix segfault on syntax error") attempted to fix a
segfault on syntax errors, but it broke Ctrl-C handling, and the
assumption that it made, that rcode could not be -1, is incorrect.
Revert this change.

Reported-by: Stephen Warren <swarren@wwwdotorg.org>
Reported-by: Przemyslaw Marczak <p.marczak@samsung.com>
Signed-off-by: Rabin Vincent <rabin@rab.in>