TTY: synclink_cs, sanitize fail paths

We will need to change the order of tty and pcmcia drivers
initializations (see the reason later in this series). And the fail
path handling is currently performed in a separate function that as
well takes care of proper deinitialization in module_exit. It is hard
to read and will need to be adjusted by our changes anyway. Instead,
get rid of this helper function and do the fail paths handling
directly in the init function. (And move the body of the function to
module_exit.)

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Acked-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>