Fix slock to work with /etc/passwd without /etc/shadow.
while we're at it, remove an occurence of trailing whitespace.
        rval =  pw->pw_passwd;
 
 #if HAVE_SHADOW_H
-       if (strlen(rval) >= 1) { /* kludge, assumes pw placeholder entry has len >= 1 */
+       if (rval[0] == 'x' && rval[1] == '\0') {
                struct spwd *sp;
                sp = getspnam(getenv("USER"));
                if(!sp)
                                        --len;
                                break;
                        default:
-                               if(num && !iscntrl((int) buf[0]) && (len + num < sizeof passwd)) { 
+                               if(num && !iscntrl((int) buf[0]) && (len + num < sizeof passwd)) {
                                        memcpy(passwd + len, buf, num);
                                        len += num;
                                }