ath10k: fix ath10k_bmi_read32 macro

tmp may be used uninitialized if ath10k_bmi_read_memory() returns
an error.
Signed-off-by: Frederic Danis <frederic.danis@linux.intel.com>
Signed-off-by: Kalle Valo <kvalo@qca.qualcomm.com>

drivers/net/wireless/ath/ath10k/bmi.h

@@ -201,7 +201,8 @@ int ath10k_bmi_write_memory(struct ath10k *ar, u32 address,
 									\
 		addr = host_interest_item_address(HI_ITEM(item));	\
 		ret = ath10k_bmi_read_memory(ar, addr, (u8 *)&tmp, 4); \
-		*val = __le32_to_cpu(tmp);				\
+		if (!ret)						\
+			*val = __le32_to_cpu(tmp);			\
 		ret;							\
 	 })