package: PVS-Studio V595 'm_pData' pointer could be null
package: PVS-Studio V595 'm_pData' pointer could be null

... so convert the last member of StorInternalData_Impl that needs
manual cleanup to rtl::Reference

Change-Id: Ie1549c1f52d50dc3c63715176c02821b63c7cab1

JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core