USB: serial: kl5kusb105: abort on open exception path

Function klsi_105_open() calls usb_control_msg() (to "enable read") and
checks its return value. When the return value is unexpected, it only
assigns the error code to the return variable retval, but does not
terminate the exception path. This patch fixes the bug by inserting
"goto err_generic_close;" when the call to usb_control_msg() fails.

Fixes: 1da177e4 ("Linux-2.6.12-rc2")
Signed-off-by: Pan Bian <bianpan2016@163.com>
[johan: rebase on prerequisite fix and amend commit message]
Signed-off-by: Johan Hovold <johan@kernel.org>