wpa_cli: Add newline to end of responses in interactive mode

wpa_cli: Add newline to end of responses in interactive mode

Some of the wpa_supplicant control interface commands, like WPS_PIN,
may not include a newline in the end of the response. This can result
in the response being lost when wpa_cli redraws the screen after an
event message. Add a newline after such responses in interactive mode
to avoid the problem.