exportfs: add module description

Every loadable module should have a description, to avoid a warning such as:

WARNING: modpost: missing MODULE_DESCRIPTION() in fs/exportfs/exportfs.o

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Link: https://lore.kernel.org/r/20250324173242.1501003-1-arnd@kernel.org
Signed-off-by: Christian Brauner <brauner@kernel.org>

Author: arndb

fs/exportfs/expfs.c

@@ -608,4 +608,5 @@ struct dentry *exportfs_decode_fh(struct vfsmount *mnt, struct fid *fid,
 }
 EXPORT_SYMBOL_GPL(exportfs_decode_fh);
 
+MODULE_DESCRIPTION("Code mapping from inodes to file handles");
 MODULE_LICENSE("GPL");