FreeBSD: Remove an incorrect assertion in zfs_getpages()

The pages in the array may become valid after this initial unbusying,
so the assertion only holds during the first iteration of the outer
loop.

Later in zfs_getpages(), the dmu_read_pages() loop handles already-valid
pages.  Just drop the assertion, it's not terribly useful.

Reviewed-by: Alexander Motin <[email protected]>
Reviewed-by: Brian Behlendorf <[email protected]>
Reviewed-by: Brian Atkinson <[email protected]>
Reported-by: Peter Holm <[email protected]>
Signed-off-by: Mark Johnston <[email protected]>
Sponsored-by: Klara, Inc.
Closes #16810
Closes #16834

Author: markjdb

module/os/freebsd/zfs/zfs_vnops_os.c

@@ -3960,10 +3960,8 @@ zfs_getpages(struct vnode *vp, vm_page_t *ma, int count, int *rbehind,
 			 * to the page fault handler's OOM logic, but this is
 			 * the best we can do for now.
 			 */
-			for (int i = 0; i < count; i++) {
-				ASSERT(vm_page_none_valid(ma[i]));
+			for (int i = 0; i < count; i++)
 				vm_page_xunbusy(ma[i]);
-			}
 
 			lr = zfs_rangelock_enter(&zp->z_rangelock,
 			    rounddown(start, blksz), len, RL_READER);