[PATCH] ieee802154/adf7242: check status of adf7242_read_reg

[trix]

From: Tom Rix <t...@redhat.com>

Clang static analysis reports this error

adf7242.c:887:6: warning: Assigned value is garbage or undefined
        len = len_u8;
            ^ ~~~~~~

len_u8 is set in
       adf7242_read_reg(lp, 0, &len_u8);

When this call fails, len_u8 is not set.

So check the return code.

Fixes: 7302b9d90117 ("ieee802154/adf7242: Driver for ADF7242 MAC IEEE802154")

Signed-off-by: Tom Rix <t...@redhat.com>
---
 drivers/net/ieee802154/adf7242.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ieee802154/adf7242.c b/drivers/net/ieee802154/adf7242.c
index c11f32f644db..7db9cbd0f5de 100644
--- a/drivers/net/ieee802154/adf7242.c
+++ b/drivers/net/ieee802154/adf7242.c
@@ -882,7 +882,9 @@ static int adf7242_rx(struct adf7242_local *lp)
        int ret;
        u8 lqi, len_u8, *data;
 
-       adf7242_read_reg(lp, 0, &len_u8);
+       ret = adf7242_read_reg(lp, 0, &len_u8);
+       if (ret)
+               return ret;
 
        len = len_u8;
 
-- 
2.18.1