Update sane.man to index xerox_mfp backend.

doc/sane.man

@@ -524,6 +524,12 @@ The sane\-umax1220u backend supports the UMAX Astra 1220U (USB) flatbed scanner
 (and also the UMAX Astra 2000U, sort of). See
 .BR sane\-umax1220u (5)
 for details.
+.TP
+.B xerox_mfp
+The sane\-xerox_mfp backend supports multiple Samsung-based Samsung, Xerox, and Dell
+scanners. See
+.BR sane\-xerox_mfp (5)
+for details.
 .PP
 Also, have a look at the backend information page at
 .I http://www.sane\-project.org/sane\-supported\-devices.html
@@ -918,6 +924,7 @@ for details).
 .BR sane\-umax_pp (5),
 .BR sane\-usb (5),
 .BR sane\-v4l (5)
+.BR sane\-xerox_mfp (5)
 
 .SH AUTHOR
 David Mosberger-Tang and many many more (see