local: Move timeout check after enabling the buffer
local: Move timeout check after enabling the buffer

We'll always get a timeout when checking data is available if the buffer has not
been enabled yet. So move this check after enabling the buffer.

Signed-off-by: Lars-Peter Clausen <3318dc5ce3e4fb7c28a0b841b6801c884e1d0896@metafoo.de>

Sunderfield/libiio,sensarliar/libiio,gburca/libiio,analogdevicesinc/libiio,Sunderfield/libiio,analogdevicesinc/libiio,gburca/libiio,Sunderfield/libiio,analogdevicesinc/libiio,sensarliar/libiio,gburca/libiio,analogdevicesinc/libiio,sensarliar/libiio