constify dentry_operations: FAT

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/fs/fat/namei_msdos.c b/fs/fat/namei_msdos.c
index 7ba03a4..da3f361 100644
--- a/fs/fat/namei_msdos.c
+++ b/fs/fat/namei_msdos.c
@@ -188,7 +188,7 @@
 	goto out;
 }
 
-static struct dentry_operations msdos_dentry_operations = {
+static const struct dentry_operations msdos_dentry_operations = {
 	.d_hash		= msdos_hash,
 	.d_compare	= msdos_cmp,
 };