staging: ks7010: fix error paths in ks7010_sdio_remove function

staging: ks7010: fix error paths in ks7010_sdio_remove function

This commit reviews and fixes error paths in ks7010_sdio_remove
driver function. It change logic to handle error directly
after priv dereference to avoid one level indentation. It also
removes a temporal netdev variable which wasn't being used in all
of the function calls. Also if send_stop_request call fails it
was making a direct 'return' instead of doing a properly cleaning.
Because of this a new 'err_free_card' label has been added.

Signed-off-by: Sergio Paracuellos <sergio.paracuellos@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>