usbip: prevent leaking socket pointer address in messages

usbip driver is leaking socket pointer address in messages. Remove
the messages that aren't useful and print sockfd in the ones that
are useful for debugging.

Signed-off-by: Shuah Khan <shuahkh@osg.samsung.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>