efi_loader: correct EFI_DEBUG_TABLE_ENTRY_SIZE

efi_loader: correct EFI_DEBUG_TABLE_ENTRY_SIZE

With the current code we allocate to little memory when adding entries to
the EFI_DEBUG_INFO_TABLE and we fail to correctly move entries when an
entry is removed.

EFI_DEBUG_TABLE_ENTRY_SIZE must be the size of an entry in the
EFI_DEBUG_INFO_TABLE, not the size of a pointer.

Fixes: 146546138af5 ("efi: add EFI_DEBUG_IMAGE_INFO for debug")
Addresses-Coverity-ID: CID 569498: Code maintainability issues (SIZEOF_MISMATCH)
Reviewed-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>