kobject: samples: make SAMPLE_KOBJECT module-only

With SAMPLE_KOBJECT=y, it isn't even linked into the kernel image.

Signed-off-by: Michal Marek <mmarek@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/samples/Kconfig b/samples/Kconfig
index b75d28c..428b065 100644
--- a/samples/Kconfig
+++ b/samples/Kconfig
@@ -26,7 +26,8 @@
 	  This build trace event example modules.
 
 config SAMPLE_KOBJECT
-	tristate "Build kobject examples"
+	tristate "Build kobject examples -- loadable modules only"
+	depends on m
 	help
 	  This config option will allow you to build a number of
 	  different kobject sample modules showing how to use kobjects,