wifi: ath5k: ath5k_hw_get_median_noise_floor(): use swap()

coccinielle reported the following:
./drivers/net/wireless/ath/ath5k/phy.c:1573:25-26: WARNING opportunity for swap()

while trying to fix the above warning, it reveals that ath5k_hw_get_median_noise_floor()
had open-coded sort() functionality. Since ath5k_hw_get_median_noise_floor() only
executes once every 10 seconds, any extra overhead due to sort() calling
its "compare" and "swap" functions can be ignored, so replace the
existing logic with a call to sort().
Signed-off-by: Mahmoud Maatuq <mahmoudmatook.mm@gmail.com>
Suggested-by: Jiri Slaby <jirislaby@kernel.org>
Signed-off-by: Kalle Valo <quic_kvalo@quicinc.com>
Link: https://lore.kernel.org/r/20230815040819.649455-1-mahmoudmatook.mm@gmail.com

drivers/net/wireless/ath/ath5k/phy.c

@@ -26,6 +26,7 @@
 
 #include <linux/delay.h>
 #include <linux/slab.h>
+#include <linux/sort.h>
 #include <asm/unaligned.h>
 
 #include "ath5k.h"
@@ -1554,6 +1555,11 @@ static void ath5k_hw_update_nfcal_hist(struct ath5k_hw *ah, s16 noise_floor)
 	hist->nfval[hist->index] = noise_floor;
 }
 
+static int cmps16(const void *a, const void *b)
+{
+	return *(s16 *)a - *(s16 *)b;
+}
+
 /**
  * ath5k_hw_get_median_noise_floor() - Get median NF from history buffer
  * @ah: The &struct ath5k_hw
@@ -1561,25 +1567,16 @@ static void ath5k_hw_update_nfcal_hist(struct ath5k_hw *ah, s16 noise_floor)
 static s16
 ath5k_hw_get_median_noise_floor(struct ath5k_hw *ah)
 {
-	s16 sort[ATH5K_NF_CAL_HIST_MAX];
-	s16 tmp;
-	int i, j;
-
-	memcpy(sort, ah->ah_nfcal_hist.nfval, sizeof(sort));
-	for (i = 0; i < ATH5K_NF_CAL_HIST_MAX - 1; i++) {
-		for (j = 1; j < ATH5K_NF_CAL_HIST_MAX - i; j++) {
-			if (sort[j] > sort[j - 1]) {
-				tmp = sort[j];
-				sort[j] = sort[j - 1];
-				sort[j - 1] = tmp;
-			}
-		}
-	}
+	s16 sorted_nfval[ATH5K_NF_CAL_HIST_MAX];
+	int i;
+
+	memcpy(sorted_nfval, ah->ah_nfcal_hist.nfval, sizeof(sorted_nfval));
+	sort(sorted_nfval, ATH5K_NF_CAL_HIST_MAX, sizeof(s16), cmps16, NULL);
 	for (i = 0; i < ATH5K_NF_CAL_HIST_MAX; i++) {
 		ATH5K_DBG(ah, ATH5K_DEBUG_CALIBRATE,
-			"cal %d:%d\n", i, sort[i]);
+			"cal %d:%d\n", i, sorted_nfval[i]);
 	}
-	return sort[(ATH5K_NF_CAL_HIST_MAX - 1) / 2];
+	return sorted_nfval[(ATH5K_NF_CAL_HIST_MAX - 1) / 2];
 }
 
 /**