jsm: removing the uart structure and filename on error

If jsm fails to load, then remove the uart stuff, otherwise,
the things (as files), will be there forever (even when the module
is unloaded). If you try to reload the module, the following message
appears:

kobject_add_internal failed for ttyn1 with -EEXIST, don't try to
register things with the same name in the same directory.

This patch remove the uart things when the driver fails.

Signed-off-by: Breno Leitao <leitao@linux.vnet.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>