[PATCH 3/5] mt76: fix a leaked reference by adding a missing of_node_put

[Wen Yang]

The call to of_find_node_by_phandle returns a node pointer with refcount
incremented thus it must be explicitly decremented after the last
usage.

Detected by coccinelle with the following warnings:
./drivers/net/wireless/mediatek/mt76/eeprom.c:58:2-8: ERROR: missing 
of_node_put; acquired a node pointer with refcount incremented on line 48, but 
without a corresponding object release within this function.
./drivers/net/wireless/mediatek/mt76/eeprom.c:61:2-8: ERROR: missing 
of_node_put; acquired a node pointer with refcount incremented on line 48, but 
without a corresponding object release within this function.
./drivers/net/wireless/mediatek/mt76/eeprom.c:67:2-8: ERROR: missing 
of_node_put; acquired a node pointer with refcount incremented on line 48, but 
without a corresponding object release within this function.
./drivers/net/wireless/mediatek/mt76/eeprom.c:70:2-8: ERROR: missing 
of_node_put; acquired a node pointer with refcount incremented on line 48, but 
without a corresponding object release within this function.
./drivers/net/wireless/mediatek/mt76/eeprom.c:72:1-7: ERROR: missing 
of_node_put; acquired a node pointer with refcount incremented on line 48, but 
without a corresponding object release within this function.

Signed-off-by: Wen Yang <wen.yan...@zte.com.cn>
Cc: Felix Fietkau <n...@nbd.name>
Cc: Lorenzo Bianconi <lorenzo.biancon...@gmail.com>
Cc: Kalle Valo <kv...@codeaurora.org>
Cc: "David S. Miller" <da...@davemloft.net>
Cc: Matthias Brugger <matthias....@gmail.com>
Cc: linux-wirel...@vger.kernel.org
Cc: netdev@vger.kernel.org
Cc: linux-arm-ker...@lists.infradead.org
Cc: linux-media...@lists.infradead.org
Cc: linux-ker...@vger.kernel.org
---
 drivers/net/wireless/mediatek/mt76/eeprom.c | 24 ++++++++++++++++--------
 1 file changed, 16 insertions(+), 8 deletions(-)

diff --git a/drivers/net/wireless/mediatek/mt76/eeprom.c 
b/drivers/net/wireless/mediatek/mt76/eeprom.c
index 530e559..a1529920d 100644
--- a/drivers/net/wireless/mediatek/mt76/eeprom.c
+++ b/drivers/net/wireless/mediatek/mt76/eeprom.c
@@ -54,22 +54,30 @@ mt76_get_of_eeprom(struct mt76_dev *dev, int len)
                part = np->name;
 
        mtd = get_mtd_device_nm(part);
-       if (IS_ERR(mtd))
-               return PTR_ERR(mtd);
+       if (IS_ERR(mtd)) {
+               ret =  PTR_ERR(mtd);
+               goto out_put_node;
+       }
 
-       if (size <= sizeof(*list))
-               return -EINVAL;
+       if (size <= sizeof(*list)) {
+               ret = -EINVAL;
+               goto out_put_node;
+       }
 
        offset = be32_to_cpup(list);
        ret = mtd_read(mtd, offset, len, &retlen, dev->eeprom.data);
        put_mtd_device(mtd);
        if (ret)
-               return ret;
+               goto out_put_node;
 
-       if (retlen < len)
-               return -EINVAL;
+       if (retlen < len) {
+               ret = -EINVAL;
+               goto out_put_node;
+       }
 
-       return 0;
+out_put_node:
+       of_node_put(np);
+       return ret;
 #else
        return -ENOENT;
 #endif
-- 
2.9.5