usbip: vudc: Fix apparent cut-n-paste error

Coverity picked up that this looks like a cut-n-paste from an almost
identical sequence below that didn't get its variable renamed.

Signed-off-by: Dave Jones <davej@codemonkey.org.uk>
Reviewed-by: Krzysztof Opasiak <k.opasiak@samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>