hush: fix handling of \^C and "^C"

function                                             old     new   delta
parse_stream                                        2238    2252     +14
encode_string                                        243     256     +13
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 2/0 up/down: 27/0)               Total: 27 bytes

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
9 files changed