firmware: dmi: struct dmi_header should be packed

Apparently the compiler does fine without it, but it feels safer and
clearer to add the missing attribute.

Signed-off-by: Jean Delvare <jdelvare@suse.de>
diff --git a/include/linux/dmi.h b/include/linux/dmi.h
index 2f9f988..5055ac3 100644
--- a/include/linux/dmi.h
+++ b/include/linux/dmi.h
@@ -75,7 +75,7 @@
 	u8 type;
 	u8 length;
 	u16 handle;
-};
+} __packed;
 
 struct dmi_device {
 	struct list_head list;