Merge tag 'efi-2021-04-rc1-3' of https://gitlab.denx.de/u-boot/custodians/u-boot-efi

Pull request for UEFI sub-system for efi-2021-04-rc1-3

Bug fixes for UEFI sub-system:

* correct value of  EFI_BLOCK_IO_PROTOCOL.Media.LastBlock
* correct GUID when closing of EFI_LOAD_FILE_PROTOCOL
* error handling in mkeficapsule tool

Bug fixes for FAT file system:

* consistent error handling for flush dir()