FIJISettingsViewer: fix driver selection & validation due to early net validation

bin/Tk/FIJISettingsViewer.pm

@@ -1015,10 +1015,11 @@ sub _add_fiu_widgets {
                 $self->_validate_fiu_entry(1, $net_entry, 'FIU_NET_NAME', $i, @{$netname}[0]);
                 $self->_validate_fiu_entry(1, $drv_entry, 'FIU_DRIVER_PATH', $i, $fiu->{'FIU_DRIVER_PATH'});
             } elsif (@{$netname} > 0) {
+                my $old_netname = $fiu->{'FIU_NET_NAME'};
                 $rv = $self->_validate_fiu_entry(0, $net_entry, 'FIU_NET_NAME', $i, @{$netname}[0]);
                 # If the new value differs from the previous one we need to do some work...
-                if (@{$netname}[0] ne $fiu->{'FIU_NET_NAME'}) {
-                    $fiu->{'FIU_NET_NAME'} = @{$netname}[0];
+                # also, ignore the validation result because the previous one is still valid.
+                if (@{$netname}[0] ne $old_netname) {
                     $fiu->{'FIU_DRIVER_PATH'} = "";
                     if (defined($rv)) {
                         Tk::FIJIUtils::show_warning($self, $rv);