Fix a (false positive?) Argument cannot be negative coverity defect.

Rather than guarding close(fd) with an fd >= 0 test and setting fd
to -1 when it is closed to avoid a potential double-close, just
move the close() call after the conditional "goto make_token".  This
moves the close() call totally outside the loop to avoid the
possibility of calling it twice.  This should also prevent a Coverity
warning about checking fd for validity after it was previously passed
to read().

Reported by:	Coverity
CID:		1355335
MFC after:	1 week
X-MFC with:	r299484

usr.bin/random/randomize_fd.c

@@ -199,17 +199,14 @@ randomize_fd(int fd, int type, int unique, double denom)
 		}
 	}
 
-	if (fd >= 0) {
-		(void)close(fd);
-		fd = -1;
-	}
-
 	/* Necessary evil to compensate for files that don't end with a newline */
 	if (bufc != i) {
 		i--;
 		goto make_token;
 	}
 
+	(void)close(fd);
+
 	free(buf);
 
 	for (i = numnode; i > 0; i--) {