[PATCH] mount: Make function to_mnt_ns static

[Mathieu Malaterre <malat@xxxxxxxxxx>]

In commit 58be28256d98 ("make mntns ->get()/->put()/->install()/->inum()
work with &mnt_ns->ns"), a new function `to_mnt_ns` was introduced.
Since this function can be made static, make it so.

Fix warning when compiling with W=1:

  fs/namespace.c:1693:23: warning: no previous prototype for ‘to_mnt_ns’ [-Wmissing-prototypes]

Signed-off-by: Mathieu Malaterre <malat@xxxxxxxxxx>
---
 fs/namespace.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/namespace.c b/fs/namespace.c
index a7f91265ea67..f0cf252d9aa3 100644
--- a/fs/namespace.c
+++ b/fs/namespace.c
@@ -1690,7 +1690,7 @@ static bool is_mnt_ns_file(struct dentry *dentry)
 	       dentry->d_fsdata == &mntns_operations;
 }
 
-struct mnt_namespace *to_mnt_ns(struct ns_common *ns)
+static struct mnt_namespace *to_mnt_ns(struct ns_common *ns)
 {
 	return container_of(ns, struct mnt_namespace, ns);
 }
-- 
2.19.2