nl80211: Work around error case prints for nl_recvmsgs on Android

nl80211: Work around error case prints for nl_recvmsgs on Android

I got the below prints on a particular Android platform:

I/wpa_supplicant( 2637): nl80211: send_and_recv->nl_recvmsgs failed: 20
I/wpa_supplicant( 2637): nl80211: send_and_recv->nl_recvmsgs failed: 20

In JellyBean libnl_2 code, I see that the nl_recvmsgs returns postive values
too. In some cases, nl_recvmgs return the output of nl_recv function. nl_recv
function can return Number of bytes read, 0 or a negative error code.

Looks like this positive return value for nl_recvmsgs may be specific to
Android. While this is not how the API is supposed to work, this does no
harm with upstream libnl which returns only 0 or -1 from the function.

Signed-off-by: Jithu Jance <jithu@broadcom.com>