ath9k: reorder error codes for spectral

When using the spectral scan feature, frames with phy errors are
returned for further processing to the driver. However, if the frames
also have an invalid CRC (which seems to happen quite often), the frame
is marked with bad CRC and not with the PHY error bit. The FFT
processing function will thus miss the frames.

Fix this by changing the precedence in error marking.

Signed-off-by: Simon Wunderlich <siwu@hrz.tu-chemnitz.de>
Signed-off-by: Mathias Kretschmer <mathias.kretschmer@fokus.fraunhofer.de>
Signed-off-by: John W. Linville <linville@tuxdriver.com>