Make clear that -w gets an argument. Add __FBSDID and remove unused

#include

usr.bin/fold/fold.1

@@ -48,10 +48,10 @@ is a filter which folds the contents of the specified files,
 or the standard input if no files are specified,
 breaking the lines to have a maximum of 80 characters.
 .Pp
-The options are as follows:
+The following option is available:
 .Bl -tag -width indent
-.It Fl w
-Specifies a line width to use instead of the default 80 characters.
+.It Fl w Ar width
+Specify a line width to use instead of the default 80 characters.
 .Ar Width
 should be a multiple of 8 if tabs are present, or the tabs should
 be expanded using

usr.bin/fold/fold.c

@@ -44,14 +44,14 @@ static const char copyright[] =
 #if 0
 static char sccsid[] = "@(#)fold.c	8.1 (Berkeley) 6/6/93";
 #endif
-static const char rcsid[] =
-  "$FreeBSD$";
 #endif /* not lint */
 
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
 #include <err.h>
 #include <stdio.h>
 #include <stdlib.h>
-#include <string.h>
 #include <unistd.h>
 
 #define	DEFLINEWIDTH	80