Fix mount point list for AIX and NetBSD.

--- Fl_Unix_System_Driver.cxx.orig	2024-03-25 10:16:04.129135656 +0100
+++ Fl_Unix_System_Driver.cxx	2024-03-25 10:16:04.126971134 +0100
@@ -278,7 +278,9 @@
   struct vmount *vp;
 
   // We always have the root filesystem
-  add("/", icon);
+  browser->add("/", icon);
+  num_files++;
+
   // Get the required buffer size for the vmount structures
   res = mntctl(MCTL_QUERY, sizeof(len), (char *) &len);
   if (!res) {
@@ -292,13 +294,15 @@
       if (0 >= res) {
         res = -1;
       } else {
-        for (int i = 0, vp = (struct vmount *) list; i < res; ++i) {
+        vp = (struct vmount *) list;
+        for (int i = 0; i < res; ++i) {
           name = (char *) vp + vp->vmt_data[VMT_STUB].vmt_off;
           strlcpy(filename, name, lname);
           // Skip the already added root filesystem
           if (strcmp("/", filename) != 0) {
             strlcat(filename, "/", lname);
             browser->add(filename, icon);
+            num_files++;
           }
           vp = (struct vmount *) ((char *) vp + vp->vmt_length);
         }
@@ -317,6 +321,8 @@
 
   // We always have the root filesystem
   browser->add("/", icon);
+  num_files++;
+
 #  ifdef HAVE_PTHREAD
   // Lock mutex for thread safety
   if (!pthread_mutex_lock(&getvfsstat_mutex)) {
@@ -330,6 +336,7 @@
         if (strcmp("/", filename) != 0) {
           strlcat(filename, "/", lname);
           browser->add(filename, icon);
+          num_files++;
         }
       }
     } else {