revoke.2: Remove mention of block special device files

Block devices are a thing of a past in FreeBSD.

Reviewed by:	ziaee
MFC after:	3 days
Differential Revision:	https://reviews.freebsd.org/D53332

lib/libsys/revoke.2

@@ -28,7 +28,7 @@
 .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 .\" SUCH DAMAGE.
 .\"
-.Dd January 25, 2016
+.Dd October 24, 2025
 .Dt REVOKE 2
 .Os
 .Sh NAME
@@ -62,7 +62,7 @@ using a special close method which does not block.
 Access to a file may be revoked only by its owner or the super user.
 The
 .Fn revoke
-system call is currently supported only for block and character special
+system call is currently supported only for character special
 device files.
 It is normally used to prepare a terminal device for a new login session,
 preventing any access by a previous user of the terminal.