staging: speakup: fix memory leak

speakup_init() didn't free first_console if speakup_kobj_init() fails.
Also propagate speakup_kobj_init()'s return code.

Signed-off-by: Vasiliy Kulikov <segooon@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>