staging: rtl8723bs: initialize le_tmp64 in rtw_BIP_verify()

Initialize le_tmp64 to zero in rtw_BIP_verify() to prevent using
uninitialized data.

Smatch warns that only 6 bytes are copied to this 8-byte (u64)
variable, leaving the last two bytes uninitialized:

drivers/staging/rtl8723bs/core/rtw_security.c:1308 rtw_BIP_verify()
warn: not copying enough bytes for '&le_tmp64' (8 vs 6 bytes)

Initializing the variable at the start of the function fixes this
warning and ensures predictable behavior.

Fixes: 554c0a3 ("staging: Add rtl8723bs sdio wifi driver")
Cc: stable <stable@kernel.org>
Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
Closes: https://lore.kernel.org/linux-staging/abvwIQh0CHTp4wNJ@stanley.mountain/
Signed-off-by: Lin YuChen <starpt.official@gmail.com>
Reviewed-by: Dan Carpenter <dan.carpenter@linaro.org>
Link: https://patch.msgid.link/20260320172502.167332-1-starpt.official@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Author: Lin YuChen

drivers/staging/rtl8723bs/core/rtw_security.c

@@ -1285,7 +1285,7 @@ u32 rtw_BIP_verify(struct adapter *padapter, u8 *precvframe)
 	u8 mic[16];
 	struct mlme_ext_priv *pmlmeext = &padapter->mlmeextpriv;
 	__le16 le_tmp;
-	__le64 le_tmp64;
+	__le64 le_tmp64 = 0;
 
 	ori_len = pattrib->pkt_len - WLAN_HDR_A3_LEN + BIP_AAD_SIZE;
 	BIP_AAD = kzalloc(ori_len, GFP_KERNEL);