hostapd: fix incorrect service name

hostapd: fix incorrect service name

When retrieving the PID for hostapd and wpa_supplicant via ubus the
wrong service name is currently used. This leads to the following error
in the log:

netifd: radio0 (1409): WARNING (wireless_add_process):
executable path /usr/sbin/wpad does not match process  path (/proc/exe)

Fixing the service name retrieves the correct PID and therefore the
warning won't occur.

Signed-off-by: David Bauer <[email protected]>