Comment 18 for bug 1861235

Thanks Colin!

[ 271.628232] dnone_free_ramge: nblks = 0, trunc = 1, len = 18446744073709551615, blkshift = 0
[ 271.628297] dnode_free_range: nblks == 0, len == 18446744073709551615
               , off=0
[ 271.628298] range_tree_clear: size == 0
[ 271.628375] range_tree_find_impl: size == 0
[ 271.628393] VERIFY(size != 0) failed
[ 271.628409] PANIC at range_tree.c:168:range_tree_add()
[ 271.628429] Showing stack for process 7960
[ 271.628432] CPU: 26 PID: 7960 Comm: receive_writer Tainted: P OE 4.15.0-99-generic #100-Ubuntu
[ 271.628433] Hardware name: Supermicro SSG-6038R-E1CR16L/X10DRH-iT, BIOS 2.0 12/17/2015
[ 271.628433] Call Trace:
[ 271.628442] dump_stack+0x6d/0x8e
[ 271.628458] spl_dumpstack+0x42/0x50 [spl]
[ 271.628462] spl_panic+0xc8/0x110 [spl]
[ 271.628468] ? vt_console_print+0x240/0x410
[ 271.628473] ? console_unlock+0x2a1/0x560
[ 271.628475] ? vprintk_emit+0x104/0x2c0
[ 271.628477] ? vprintk_default+0x29/0x50
[ 271.628479] ? printk+0x52/0x6e
[ 271.628566] range_tree_add+0x29b/0x300 [zfs]
[ 271.628600] ? range_tree_clear+0xa4/0xb0 [zfs]
[ 271.628602] ? printk+0x52/0x6e
[ 271.628635] dnode_free_range+0x178/0x720 [zfs]
[ 271.628673] dmu_object_free+0x6d/0xc0 [zfs]
[ 271.628698] dmu_free_long_object+0x9f/0xc0 [zfs]
[ 271.628723] receive_freeobjects.isra.12+0x7a/0x100 [zfs]
[ 271.628747] receive_writer_thread+0x6d2/0xa60 [zfs]
[ 271.628750] ? set_curr_task_fair+0x2b/0x60
[ 271.628753] ? spl_kmem_free+0x33/0x40 [spl]
[ 271.628757] ? kfree+0x162/0x180
[ 271.628781] ? receive_free.isra.13+0xc0/0xc0 [zfs]
[ 271.628785] thread_generic_wrapper+0x74/0x90 [spl]
[ 271.628788] kthread+0x121/0x140
[ 271.628791] ? __thread_exit+0x20/0x20 [spl]
[ 271.628792] ? kthread_create_worker_on_cpu+0x70/0x70
[ 271.628796] ret_from_fork+0x35/0x40