USB: serial: io_edgeport: fix memory leaks in attach error path

USB: serial: io_edgeport: fix memory leaks in attach error path

Orabug: 25256927

[ Upstream commit c5c0c55598cefc826d6cfb0a417eeaee3631715c ]

Private data, URBs and buffers allocated for Epic devices during
attach were never released on errors (e.g. missing endpoints).

Fixes: 6e8cf7751f9f ("USB: add EPIC support to the io_edgeport driver")
Cc: stable <stable@vger.kernel.org>	# v2.6.21
Signed-off-by: Johan Hovold <johan@kernel.org>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
(cherry picked from commit 7bbc1379766b1887cd7b3c225c78acca5b82ec5e)
Signed-off-by: Dhaval Giani <dhaval.giani@oracle.com>