The EFI stub must not use any KASAN instrumented code as the kernel
proper did not initialize the thread pointer and the mapping for the
KASAN shadow region.

Avoid using the generic strcmp function, instead use the one in
drivers/firmware/efi/libstub/string.c.
Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com>
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Reviewed-by: Atish Patra <atishp@rivosinc.com>
Link: https://lore.kernel.org/r/20230203075232.274282-5-alexghiti@rivosinc.comSigned-off-by: Palmer Dabbelt <palmer@rivosinc.com>