[tools] testbot/web: Document why ErrField is not set when failing to delete an item.

[Francois Gouget]

Signed-off-by: Francois Gouget 
---
 testbot/web/admin/UsersList.pl | 3 ++-
 testbot/web/admin/VMsList.pl   | 3 ++-
 2 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/testbot/web/admin/UsersList.pl b/testbot/web/admin/UsersList.pl
index 019bc6328..ae514e901 100644
--- a/testbot/web/admin/UsersList.pl
+++ b/testbot/web/admin/UsersList.pl
@@ -117,7 +117,8 @@ sub OnItemAction($$$$)
   if ($Action eq "Delete")
   {
     $User->Status('deleted');
-    (my $ErrProperty, $self->{ErrMessage}) = $User->Save();
+    # Setting $self->{ErrField} is only useful on form pages
+    (my $_ErrProperty, $self->{ErrMessage}) = $User->Save();
     return 0 if (defined $self->{ErrMessage});

# Forcefully log out that user by deleting the web sessions
diff --git a/testbot/web/admin/VMsList.pl b/testbot/web/admin/VMsList.pl
index 0ed0b0d0b..18952253f 100644
--- a/testbot/web/admin/VMsList.pl
+++ b/testbot/web/admin/VMsList.pl
@@ -59,7 +59,8 @@ sub OnItemAction($$$$)
   if ($Action eq "Delete")
   {
     $VM->Role("deleted");
-    (my $ErrProperty, $self->{ErrMessage}) = $VM->Save();
+    # Setting $self->{ErrField} is only useful on form pages
+    (my $_ErrProperty, $self->{ErrMessage}) = $VM->Save();
     return !defined $self->{ErrMessage};
   }