getpass: Fix a memory leak in ssh_gets() on error.
getpass: Fix a memory leak in ssh_gets() on error.

(cherry picked from commit 6092596199e8ebfbbf6e6ba48b7ec6ca0d85fa13)

mwgoldsmith/ssh,mwgoldsmith/ssh,mwgoldsmith/libssh,mwgoldsmith/libssh,mwgoldsmith/libssh,mwgoldsmith/ssh,mwgoldsmith/libssh,mwgoldsmith/ssh