lzc: move lzc_ioctl_fd() into lzc proper

Name the OS-specific call lzc_ioctl_fd_os(), and make lzc_ioctl_fd()
wrap it, so we can do more in the wrapper.

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

lib/libzfs_core/os/freebsd/libzfs_core_ioctl.c

@@ -26,6 +26,7 @@
 #include <os/freebsd/zfs/sys/zfs_ioctl_compat.h>
 #include <err.h>
 #include <libzfs_core.h>
+#include "libzfs_core_impl.h"
 
 int zfs_ioctl_version = ZFS_IOCVER_UNDEF;
 
@@ -101,7 +102,7 @@ zcmd_ioctl_compat(int fd, int request, zfs_cmd_t *zc, const int cflag)
  * error is returned zc_nvlist_dst_size won't be updated.
  */
 int
-lzc_ioctl_fd(int fd, unsigned long request, zfs_cmd_t *zc)
+lzc_ioctl_fd_os(int fd, unsigned long request, zfs_cmd_t *zc)
 {
 	size_t oldsize;
 	int ret, cflag = ZFS_CMD_COMPAT_NONE;

lib/libzfs_core/os/linux/libzfs_core_ioctl.c

@@ -23,9 +23,10 @@
 #include <sys/param.h>
 #include <sys/zfs_ioctl.h>
 #include <libzfs_core.h>
+#include "libzfs_core_impl.h"
 
 int
-lzc_ioctl_fd(int fd, unsigned long request, zfs_cmd_t *zc)
+lzc_ioctl_fd_os(int fd, unsigned long request, zfs_cmd_t *zc)
 {
 	return (ioctl(fd, request, zc));
 }