init/do_mounts.c: proper prepare_namespace() prototype

Add a proper protype for prepare_namespace() in include/linux/init.h.

Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/init/do_mounts.c b/init/do_mounts.c
index dc1ec08..3f57ed4 100644
--- a/init/do_mounts.c
+++ b/init/do_mounts.c
@@ -9,6 +9,7 @@
 #include <linux/delay.h>
 #include <linux/mount.h>
 #include <linux/device.h>
+#include <linux/init.h>
 
 #include <linux/nfs_fs.h>
 #include <linux/nfs_fs_sb.h>