net: xilinx_emacps: Disable napi when xemacps_mii_probe fails

net: xilinx_emacps: Disable napi when xemacps_mii_probe fails

In xemacps_open(), call napi_disable() when the xemacps_mii_probe() fails.
This change is needed to undo the napi_enable() which called before the
xemacps_mii_probe().

This fix is needed because of below commit
"net: xilinx_emacps: Fix race condition occurs during link up/down"
(sha1: 49028589bcd9c7d2657b3b6fec82d216a9c9f5c6)

Reported-by: Soren Brinkmann <soren.brinkmann@xilinx.com>
Signed-off-by: Punnaiah Choudary Kalluri <punnaia@xilinx.com>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>