drand48(3) returns values in [0.0, 1.0).

From j@bitminer.ca with input from Andras Farkas, deraadt, joerg@netbsd
"fix however you feel best!" jmc

src/lib/libc/stdlib/rand48.3

@@ -9,9 +9,9 @@
 .\" of any kind. I shall in no event be liable for anything that happens
 .\" to anyone/anything when using this software.
 .\"
-.\"	$OpenBSD: rand48.3,v 1.20 2015/11/10 23:48:18 jmc Exp $
+.\"	$OpenBSD: rand48.3,v 1.21 2019/12/20 19:16:40 tb Exp $
 .\"
-.Dd $Mdocdate: November 10 2015 $
+.Dd $Mdocdate: December 20 2019 $
 .Dt DRAND48 3
 .Os
 .Sh NAME
@@ -101,7 +101,7 @@ and
 return values of type double.
 The full 48 bits of r(n+1) are
 loaded into the mantissa of the returned value, with the exponent set
-such that the values produced lie in the interval [0.0, 1.0].
+such that the values produced lie in the interval [0.0, 1.0).
 .Pp
 .Fn lrand48
 and