ath11k: Fix memory leak on error path

In ath11k_mac_setup_iface_combinations(), if memory cannot be assigned
for the variable limits, then the memory assigned to combinations will
be leaked. Fix this.

Addresses-Coverity-ID: 1497534 ("Resource leaks")
Fixes: 2626c26970 ("ath11k: add interface_modes to hw_params")
Signed-off-by: Alex Dewar <alex.dewar90@gmail.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/20201004100218.311653-2-alex.dewar90@gmail.com

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

@@ -6041,8 +6041,10 @@ static int ath11k_mac_setup_iface_combinations(struct ath11k *ar)
 	n_limits = 2;
 
 	limits = kcalloc(n_limits, sizeof(*limits), GFP_KERNEL);
-	if (!limits)
+	if (!limits) {
+		kfree(combinations);
 		return -ENOMEM;
+	}
 
 	limits[0].max = 1;
 	limits[0].types |= BIT(NL80211_IFTYPE_STATION);