[GPU] Fix remaininig issue to calculate present layout's padding for KVCache (openvinotoolkit#25706)

### Details:
- Follow up remaining issue from
openvinotoolkit#25682
- Fix issue where kvcache was optimized out even if calculated present
layout's padding was negative

### Tickets:
 - 146876

Author: andrew-k-park

src/plugins/intel_gpu/src/graph/primitive_inst.cpp

@@ -1208,14 +1208,11 @@ void primitive_inst::do_runtime_in_place_kv_cache() {
     GPU_DEBUG_TRACE_DETAIL << "[do runtime kv_cache opt] " << id() << " initial present_layout : " << present_layout.to_string() << std::endl;
     GPU_DEBUG_TRACE_DETAIL << "[do runtime kv_cache opt] " << id() << " initial past_layout : " << past_layout.to_string() << std::endl;
     auto max_pad = kv_cache_inst::get_max_pad(past_layout, _deps[0].first->_max_output_layout_count[0], sequence_axis_legacy, "past_layout");
-
-    if (max_pad > 0) {
-        const auto new_seq_len = static_cast<int64_t>(new_layout.get_shape()[sequence_axis]);
-        if (max_pad - new_seq_len >= 0) {
-            kv_cache_inst::update_pad(present_layout, max_pad - new_seq_len, sequence_axis_legacy);
-            GPU_DEBUG_TRACE_DETAIL << "[do runtime_in_place_kv_cache] " << id() << " Updated present_layout's pad : "
-                                   << present_layout.to_string() << std::endl;
-        }
+    const auto new_seq_len = static_cast<int64_t>(new_layout.get_shape()[sequence_axis]);
+    // In chatbot scenario, when chat history must be stored in kvcache, new_seq_len may not be 1 even if max_pad is greater than 0
+    if (max_pad - new_seq_len >= 0) {
+        kv_cache_inst::update_pad(present_layout, max_pad - new_seq_len, sequence_axis_legacy);
+        GPU_DEBUG_TRACE_DETAIL << "[do runtime_in_place_kv_cache] " << id() << " Updated present_layout's pad : " << present_layout.to_string() << std::endl;
         auto& variable = get_network().get_variable(desc->variable_info.variable_id);
         variable.set_layout(present_layout);
         GPU_DEBUG_TRACE_DETAIL << "[do_runtime_in_place_kv_cache] " << id() << "Updated variable with present_layout"