Fix another giant batch of resource leaks. (Mostly memory, but there's

one missing fclose too.)

[originally from svn r9919]

unix/uxgen.c

@@ -26,6 +26,7 @@ char *get_random_data(int len)
 	ret = read(fd, buf+ngot, len-ngot);
 	if (ret < 0) {
 	    close(fd);
+            sfree(buf);
 	    perror("puttygen: unable to read /dev/random");
 	    return NULL;
 	}