Mark functions as static

Mark functions used only in the same translation unit as static. This
only includes functions that do not have a prototype in a header file
either.

Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu>
Closes #10470

lib/libzfs/libzfs_iter.c

@@ -38,7 +38,7 @@
 
 #include "libzfs_impl.h"
 
-int
+static int
 zfs_iter_clones(zfs_handle_t *zhp, zfs_iter_f func, void *data)
 {
 	nvlist_t *nvl = zfs_get_clones_nvl(zhp);