ath5k: clean up some comments

This fixes a few misspellings, word repetitions, and some grammar
nits in ath5k comments.  No code changes.

Signed-off-by: Bob Copeland <me@bobcopeland.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/drivers/net/wireless/ath/ath5k/eeprom.c b/drivers/net/wireless/ath/ath5k/eeprom.c
index ae316fe..39722dd 100644
--- a/drivers/net/wireless/ath/ath5k/eeprom.c
+++ b/drivers/net/wireless/ath/ath5k/eeprom.c
@@ -661,7 +661,7 @@
  * (eeprom versions < 4). For RF5111 we have 11 pre-defined PCDAC
  * steps that match with the power values we read from eeprom. On
  * older eeprom versions (< 3.2) these steps are equaly spaced at
- * 10% of the pcdac curve -until the curve reaches it's maximum-
+ * 10% of the pcdac curve -until the curve reaches its maximum-
  * (11 steps from 0 to 100%) but on newer eeprom versions (>= 3.2)
  * these 11 steps are spaced in a different way. This function returns
  * the pcdac steps based on eeprom version and curve min/max so that we
@@ -1113,7 +1113,7 @@
  */
 
 /* For RF2413 power calibration data doesn't start on a fixed location and
- * if a mode is not supported, it's section is missing -not zeroed-.
+ * if a mode is not supported, its section is missing -not zeroed-.
  * So we need to calculate the starting offset for each section by using
  * these two functions */