wifi: ath11k: mhi: fix potential memory leak in ath11k_mhi_register()

mhi_alloc_controller() allocates a memory space for mhi_ctrl. When gets
some error, mhi_ctrl should be freed with mhi_free_controller(). But
when ath11k_mhi_read_addr_from_dt() fails, the function returns without
calling mhi_free_controller(), which will lead to a memory leak.

We can fix it by calling mhi_free_controller() when
ath11k_mhi_read_addr_from_dt() fails.
Signed-off-by: Jianglei Nie <niejianglei2021@163.com>
Reviewed-by: Jeff Johnson <quic_jjohnson@quicinc.com>
Signed-off-by: Kalle Valo <quic_kvalo@quicinc.com>
Link: https://lore.kernel.org/r/20220907073704.58806-1-niejianglei2021@163.com

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

@@ -402,8 +402,7 @@ int ath11k_mhi_register(struct ath11k_pci *ab_pci)
 	ret = ath11k_mhi_get_msi(ab_pci);
 	if (ret) {
 		ath11k_err(ab, "failed to get msi for mhi\n");
-		mhi_free_controller(mhi_ctrl);
-		return ret;
+		goto free_controller;
 	}
 
 	if (!test_bit(ATH11K_FLAG_MULTI_MSI_VECTORS, &ab->dev_flags))
@@ -412,7 +411,7 @@ int ath11k_mhi_register(struct ath11k_pci *ab_pci)
 	if (test_bit(ATH11K_FLAG_FIXED_MEM_RGN, &ab->dev_flags)) {
 		ret = ath11k_mhi_read_addr_from_dt(mhi_ctrl);
 		if (ret < 0)
-			return ret;
+			goto free_controller;
 	} else {
 		mhi_ctrl->iova_start = 0;
 		mhi_ctrl->iova_stop = 0xFFFFFFFF;
@@ -440,18 +439,22 @@ int ath11k_mhi_register(struct ath11k_pci *ab_pci)
 	default:
 		ath11k_err(ab, "failed assign mhi_config for unknown hw rev %d\n",
 			   ab->hw_rev);
-		mhi_free_controller(mhi_ctrl);
-		return -EINVAL;
+		ret = -EINVAL;
+		goto free_controller;
 	}
 
 	ret = mhi_register_controller(mhi_ctrl, ath11k_mhi_config);
 	if (ret) {
 		ath11k_err(ab, "failed to register to mhi bus, err = %d\n", ret);
-		mhi_free_controller(mhi_ctrl);
-		return ret;
+		goto free_controller;
 	}
 
 	return 0;
+
+free_controller:
+	mhi_free_controller(mhi_ctrl);
+	ab_pci->mhi_ctrl = NULL;
+	return ret;
 }
 
 void ath11k_mhi_unregister(struct ath11k_pci *ab_pci)