ath5k: fix buffer overrun in rate debug code

char bname[5] is too small for the string "X GHz" when the null
terminator is taken into account.  Thus, turning on rate debugging
can crash unless we have lucky stack alignment.

Cc: stable@kernel.org
Reported-by: Paride Legovini <legovini@spiro.fisica.unipd.it>
Signed-off-by: Bob Copeland <me@bobcopeland.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

drivers/net/wireless/ath5k/debug.c

@@ -424,7 +424,7 @@ ath5k_debug_dump_bands(struct ath5k_softc *sc)
 
 	for (b = 0; b < IEEE80211_NUM_BANDS; b++) {
 		struct ieee80211_supported_band *band = &sc->sbands[b];
-		char bname[5];
+		char bname[6];
 		switch (band->band) {
 		case IEEE80211_BAND_2GHZ:
 			strcpy(bname, "2 GHz");