Change vfc_typenum back to vfc_index in response to bde's

commit to getvfsent.c rev 1.10.

lib/libc/gen/getvfsent.3

@@ -1,4 +1,4 @@
-.\"	$Id: getvfsent.3,v 1.7 1997/02/22 14:58:10 peter Exp $
+.\"	$Id: getvfsent.3,v 1.8 1997/02/28 06:22:28 mpp Exp $
 .\"	Written by Garrett A. Wollman, September 1994.
 .\"	This manual page is in the public domain.
 .\"
@@ -53,7 +53,7 @@ are as follows:
 .Bl -tag -compact -width vfc_refcount
 .It vfc_name
 the name of the filesystem
-.It vfc_typenum
+.It vfc_index
 the filesystem type number assigned by the kernel and used in calls to
 .Xr mount 2
 .It vfc_refcount