libzfs: ensure all ioctl calls go through lzc_ioctl_fd()

Sponsored-by: https://despairlabs.com/sponsor/
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Alexander Motin <mav@FreeBSD.org>
Signed-off-by: Rob Norris <robn@despairlabs.com>
Closes #17344
(cherry picked from commit f454cc1723)

lib/libzfs/os/linux/libzfs_util_os.c

@@ -53,12 +53,6 @@
 
 #define	ZDIFF_SHARESDIR		"/.zfs/shares/"
 
-int
-zfs_ioctl(libzfs_handle_t *hdl, int request, zfs_cmd_t *zc)
-{
-	return (ioctl(hdl->libzfs_fd, request, zc));
-}
-
 const char *
 libzfs_error_init(int error)
 {