oem-ibm: libpldmresponder: oem_ibm_handler: Remove unused `this`

```
../oem/ibm/libpldmresponder/oem_ibm_handler.hpp:101:14: error: lambda capture 'this' is not used [-Werror,-Wunused-lambda-capture]
  101 |             [this](sdbusplus::message_t& msg) {
      |              ^~~~
```

Change-Id: I155758a25488d747eed2af0ac24407561ab3cc9f
Signed-off-by: Andrew Jeffery <andrew@codeconstruct.com.au>
diff --git a/oem/ibm/libpldmresponder/oem_ibm_handler.hpp b/oem/ibm/libpldmresponder/oem_ibm_handler.hpp
index 6cbb901..8c164da 100644
--- a/oem/ibm/libpldmresponder/oem_ibm_handler.hpp
+++ b/oem/ibm/libpldmresponder/oem_ibm_handler.hpp
@@ -98,7 +98,7 @@
             pldm::utils::DBusHandler::getBus(),
             propertiesChanged("/xyz/openbmc_project/state/chassis0",
                               "xyz.openbmc_project.State.Chassis"),
-            [this](sdbusplus::message_t& msg) {
+            [](sdbusplus::message_t& msg) {
             pldm::utils::DbusChangedProps props{};
             std::string intf;
             msg.read(intf, props);