net: usb: smsc95xx: Fix an error code in smsc95xx_reset()

Return a negative error code instead of success.

Fixes: 2f7ca802

 ("net: Add SMSC LAN9500 USB2.0 10/100 ethernet adapter driver")
Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Link: https://lore.kernel.org/r/147927f0-9ada-45cc-81ff-75a19dd30b76@moroto.mountain
Signed-off-by: Jakub Kicinski <kuba@kernel.org>