oem-ibm: LID reads: fix vector usage

Fixed a pointer that would point to an std::vector, and would end up
being stale after said vector is resized.

Signed-off-by: Deepak Kodihalli <dkodihal@in.ibm.com>
Change-Id: I3abd63af5d159075aedae9ec3643058a808c9b8d
diff --git a/oem/ibm/libpldmresponder/file_io.cpp b/oem/ibm/libpldmresponder/file_io.cpp
index 963a6b6..be0c95b 100644
--- a/oem/ibm/libpldmresponder/file_io.cpp
+++ b/oem/ibm/libpldmresponder/file_io.cpp
@@ -638,6 +638,7 @@
     }
 
     rc = handler->read(offset, length, response);
+    responsePtr = reinterpret_cast<pldm_msg*>(response.data());
     encode_rw_file_by_type_resp(request->hdr.instance_id,
                                 PLDM_READ_FILE_BY_TYPE, rc, length,
                                 responsePtr);