Remove obsolete TODOs related to hard links in gofer.

Hard link support for synthetic files is still not supported in the gofer
client. The feature request was asked in #10143. There are clear workarounds
for that use-case as specified on the issue. There are no other use cases we
know of for synthetic file hard links. So we will close this for now.

Fixes #6739

PiperOrigin-RevId: 800956772

Author: ayushr2

pkg/sentry/fsimpl/gofer/directfs_inode.go

@@ -583,8 +583,6 @@ func (i *directfsInode) link(target *dentry, name string, d *dentry) (*dentry, e
 	}
 	// Note that we don't need to set uid/gid for the new child. This is a hard
 	// link. The original file already has the right owner.
-	// TODO(gvisor.dev/issue/6739): Hard linked dentries should share the same
-	// inode fields.
 	return i.getCreatedChild(name, auth.NoID /* uid */, auth.NoID /* gid */, false /* isDir */, true /* createDentry */, d)
 }
 

pkg/sentry/fsimpl/gofer/filesystem.go

@@ -827,7 +827,6 @@ func (fs *filesystem) LinkAt(ctx context.Context, rp *vfs.ResolvingPath, vd vfs.
 			return nil, linuxerr.EMLINK
 		}
 		if d.inode.isSynthetic() {
-			// TODO(gvisor.dev/issue/6739): Add synthetic file hard link support.
 			return nil, linuxerr.EOPNOTSUPP
 		}
 		return parent.link(ctx, d, name)

pkg/sentry/fsimpl/gofer/lisafs_inode.go

@@ -448,8 +448,6 @@ func (i *lisafsInode) link(ctx context.Context, target *lisafsInode, name string
 	if err != nil {
 		return nil, err
 	}
-	// TODO(gvisor.dev/issue/6739): Hard linked dentries should share the same
-	// inode fields.
 	return i.newChildDentry(ctx, &linkInode, name)
 }