Disable using efivars as a pstore backend by default

configname: CONFIG_EFI_VARS_PSTORE_DEFAULT_DISABLE

Linux Kernel Configuration
└─>Device Drivers
└─>Firmware Drivers
└─>EFI (Extensible Firmware Interface) Support
└─>Disable using efivars as a pstore backend by default
In linux kernel since version 3.10 (release Date: 2013-06-30)  
Saying Y here will disable the use of efivars as a storage
backend for pstore by default. This setting can be overridden
using the efivars module's pstore_disable parameter.