Fix common misspellings

Fixes generated by 'codespell' and manually reviewed.

Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>
diff --git a/drivers/net/wireless/ath/ath5k/ani.h b/drivers/net/wireless/ath/ath5k/ani.h
index d0a6640..0340153 100644
--- a/drivers/net/wireless/ath/ath5k/ani.h
+++ b/drivers/net/wireless/ath/ath5k/ani.h
@@ -27,7 +27,7 @@
 #define ATH5K_ANI_RSSI_THR_HIGH		40
 #define ATH5K_ANI_RSSI_THR_LOW		7
 
-/* maximum availabe levels */
+/* maximum available levels */
 #define ATH5K_ANI_MAX_FIRSTEP_LVL	2
 #define ATH5K_ANI_MAX_NOISE_IMM_LVL	1