ath9k: dfs_debug fix possible NULL dereference
ath9k: dfs_debug fix possible NULL dereference

Fix possible NULL (sc->dfs_detector) pointer dereference.

Detected by Smatch:
drivers/net/wireless/ath/ath9k/dfs_debug.c:67 read_file_dfs()
error: we previously assumed 'sc->dfs_detector' could be null (see line 47)

Signed-off-by: Janusz Dziedzic <a4201e08a607951e17dcd5a575c0fe6bceb34e87@tieto.com>
Signed-off-by: John W. Linville <2a53bac7a5d324865ef46ec4c38b2c0fba1456b4@tuxdriver.com>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs