p54: prevent upload of wrong firmwares

This patch will prevent anyone to upload a firmware which was not designed for his device.

There's still a catch:
There is no easy way to detect if a firmware is for PCI or for USB (1st Gen),
because they all share the same LM86 identifier.

Signed-off-by: Christian Lamparter <chunkeey@web.de>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/drivers/net/wireless/p54/p54pci.c b/drivers/net/wireless/p54/p54pci.c
index aa367a0..3f9a6b0 100644
--- a/drivers/net/wireless/p54/p54pci.c
+++ b/drivers/net/wireless/p54/p54pci.c
@@ -79,6 +79,12 @@
 	if (err)
 		return err;
 
+	if (priv->common.fw_interface != FW_LM86) {
+		dev_err(&priv->pdev->dev, "wrong firmware, "
+			"please get a LM86(PCI) firmware a try again.\n");
+		return -EINVAL;
+	}
+
 	data = (__le32 *) priv->firmware->data;
 	remains = priv->firmware->size;
 	device_addr = ISL38XX_DEV_FIRMWARE_ADDR;