tka: Revert "improve logging for Compact and Commit operations"

This reverts commit b25920dfc0.

The `log.Printf` messages are causing panics in corp, in particular:

> panic: please use tailscale.com/logger.Logf instead of the log package

Fixing the TKA code to plumb through a logger properly is going to be
a hassle, so for now remove these logs to unblock merges to corp.

Updates tailscale/corp#39455

Signed-off-by: Alex Chan <alexc@tailscale.com>

tka/tailchonk.go

@@ -597,9 +597,6 @@ func (c *FS) CommitVerifiedAUMs(updates []AUM) error {
 	for i, aum := range updates {
 		h := aum.Hash()
 		err := c.commit(h, func(info *fsHashInfo) {
-			if info.PurgedUnix > 0 {
-				log.Printf("tka: CommitVerifiedAUMs: committing previously-deleted AUM %s", h.String())
-			}
 			info.PurgedUnix = 0 // just in-case it was set for some reason
 			info.AUM = &aum
 		})
@@ -976,8 +973,5 @@ func Compact(storage CompactableChonk, head AUMHash, opts CompactionOptions) (la
 	if err := storage.SetLastActiveAncestor(lastActiveAncestor); err != nil {
 		return AUMHash{}, err
 	}
-	if len(toDelete) > 0 {
-		log.Printf("tka compaction: purging %d AUM(s) [%q]", len(toDelete), toDelete)
-	}
 	return lastActiveAncestor, storage.PurgeAUMs(toDelete)
 }