wimaxll_gnl_cb: set only ctx->result if callback said to stop
wimaxll_gnl_cb: set only ctx->result if callback said to stop

wimaxll_recv() will call this function for every message until
ctx->result stops being -EINPROGRESS. Thus, if the message handler
said to NL_STOP (which we also pass to nl_recvmsgs()), then update
ctx->result to make sure wimaxll_recv() doesn't call nl_recvmsgs any
more.

Signed-off-by: Inaky Perez-Gonzalez <32fcc484d967529190dea5c4cba96be3030624cc@linux.intel.com>

susnux/wimax-tools,ago/wimax-tools,susnux/wimax-tools,ago/wimax-tools