ath11k: fix missing free of skb on error return path

The error handling when the call to ath11k_hal_srng_get_entrysize fails
leaks skb, fix this by returning via the err_free return path that will
ensure the skb is free'd.

Addresses-Coverity: ("Resource leak")
Fixes: d5c65159 ("ath11k: driver for Qualcomm IEEE 802.11ax devices")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>

drivers/net/wireless/ath/ath11k/dp_tx.c

@@ -669,8 +669,10 @@ int ath11k_dp_tx_htt_srng_setup(struct ath11k_base *ab, u32 ring_id,
 				 HAL_ADDR_MSB_REG_SHIFT;
 
 	ret = ath11k_hal_srng_get_entrysize(ring_type);
-	if (ret < 0)
-		return -EINVAL;
+	if (ret < 0) {
+		ret = -EINVAL;
+		goto err_free;
+	}
 
 	ring_entry_sz = ret;