_gps_check_fail_status.flags.fix can never be true

[CarlOlsson]

This
https://github.com/PX4/ecl/blob/066392ef0247e010d8d10fb33fc6b5da21476227/EKF/gps_checks.cpp#L119-L119
Can never be true because collect_gps() only runs if fix_type > 2
https://github.com/PX4/ecl/blob/066392ef0247e010d8d10fb33fc6b5da21476227/EKF/estimator_interface.cpp#L214-L214

[priseborough]

For consistency with how we handle quality for other sensors, we should read in the GPS data regardless of quality and check if quality, eg fix type, meets minimum required for current use when it's popped from the buffer.