mwifiex: fix uninitialized variable access in pcie_remove

Checking the firmware status from PCIe register only works
if the register is available, otherwise we end up with
random behavior:

drivers/net/wireless/marvell/mwifiex/pcie.c: In function 'mwifiex_pcie_remove':
drivers/net/wireless/marvell/mwifiex/pcie.c:585:5: error: 'fw_status' may be used uninitialized in this function [-Werror=maybe-uninitialized]

This makes sure we treat the absence of the register as a failure.

Fixes: 045f0c1b5e26 ("mwifiex: get rid of global user_rmmod flag")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>

drivers/net/wireless/marvell/mwifiex/pcie.c

@@ -299,6 +299,8 @@ static void mwifiex_pcie_remove(struct pci_dev *pdev)
 	reg = card->pcie.reg;
 	if (reg)
 		ret = mwifiex_read_reg(adapter, reg->fw_status, &fw_status);
+	else
+		fw_status = -1;
 
 	if (fw_status == FIRMWARE_READY_PCIE && !adapter->mfg_mode) {
 		mwifiex_deauthenticate_all(adapter);