spelling: call it null-terminate consistently

With a dash, using two Ls. Also for different forms of the word.

Use NULL in all uppercase if it means a zero pointer.

Follow-up to 307b7543ea

Closes #17489

packages/OS400/rpg-examples/HEADERAPI

@@ -135,7 +135,7 @@
       *
      d len             s             10u 0
       *
-        len = %scan(X'00': string: 1: length); // Limit to zero-terminated string
+        len = %scan(X'00': string: 1: length); // Limit to null-terminated string
         if len = 0;
             len = length + 1;
         endif;

packages/OS400/rpg-examples/HTTPPOST

@@ -118,7 +118,7 @@
       *
      d len             s             10u 0
       *
-        len = %scan(X'00': string: 1: length); // Limit to zero-terminated string
+        len = %scan(X'00': string: 1: length); // Limit to null-terminated string
         if len = 0;
             len = length + 1;
         endif;

packages/OS400/rpg-examples/INMEMORY

@@ -148,7 +148,7 @@
       *
      d len             s             10u 0
       *
-        len = %scan(X'00': string: 1: length); // Limit to zero-terminated string
+        len = %scan(X'00': string: 1: length); // Limit to null-terminated string
         if len = 0;
             len = length + 1;
         endif;

packages/OS400/rpg-examples/SIMPLE1

@@ -97,7 +97,7 @@
       *
      d len             s             10u 0
       *
-     c                   eval      len = %scan(X'00': string: 1: length)        Limit 0-terminated
+     c                   eval      len = %scan(X'00': string: 1: length)        Limit null-terminated
      c                   if        len = 0
      c                   eval      len = length + 1
      c                   endif

packages/OS400/rpg-examples/SIMPLE2

@@ -97,7 +97,7 @@
 
             dcl-s len uns(10);
 
-            len = %scan(X'00': string: 1: length); // Limit to zero-terminated string
+            len = %scan(X'00': string: 1: length); // Limit to null-terminated string
             if len = 0;
                 len = length + 1;
             endif;

packages/OS400/rpg-examples/SMTPSRCMBR

@@ -228,7 +228,7 @@
      d addrdiff        s             10i 0
      d len             s             10u 0
       *
-        len = %scan(X'00': string: 1: length); // Limit to zero-terminated string
+        len = %scan(X'00': string: 1: length); // Limit to null-terminated string
         if len = 0;
             len = length + 1;
         endif;

packages/vms/curl_crtl_init.c

@@ -131,7 +131,7 @@ static int sys_trnlnm(const char *logname,
 
   if($VMS_STATUS_SUCCESS(status)) {
 
-    /* Null terminate and return the string */
+    /* Null-terminate and return the string */
     /*--------------------------------------*/
     value[result] = '\0';
   }