A handful of EFI fixes:

 - Fix/robustify a diagnostic printk
 - Fix a (normally not triggered) parser bug in the libstub code
 - Allow !EFI_MEMORY_XP && !EFI_MEMORY_RO entries in the memory map
 - Stop Risc-V from crashing on boot if there's no FDT table

Signed-off-by: Ingo Molnar <mingo@kernel.org>