If the buffer has slashes up to the end then this will read past the end
of the array. I don't anticipate that this is an issue for many people
in real life, but it's the right thing to do and it makes static
checkers happy.
Fixes: 7a88a6227dc7 ("efi/libstub: Fix path separator regression")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
c4039b29fe