Staging: workaround build system bug

This is needed as CONFIG_STAGING is set to y, yet there is no code in
drivers/staging/ to build, so the build-in.o doesn't get created
properly. Create a "dummy" module in drivers/staging called staging.c
to work around this bug.

Cc: Sam Ravnborg <[e-mail]>
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

drivers/staging/Makefile

···
 # Makefile for staging directory
 
+# fix for build system bug...
+obj-$(CONFIG_STAGING)		+= staging.o
+
 obj-$(CONFIG_ET131X)		+= et131x/
 obj-$(CONFIG_SLICOSS)		+= slicoss/
 obj-$(CONFIG_SXG)		+= sxg/

drivers/staging/staging.c

···
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/module.h>
+
+static int __init staging_init(void)
+{
+	return 0;
+}
+
+static void __exit staging_exit(void)
+{
+}
+
+module_init(staging_init);
+module_exit(staging_exit);
+
+MODULE_AUTHOR("Greg Kroah-Hartman");
+MODULE_DESCRIPTION("Staging Core");
+MODULE_LICENSE("GPL");