scripts/wrapper: fix wrong test when checking access to the reall tool

In C, the proper syntax for a bit-wise OR is a single '|', not two.

It worked so far because all was well:
- X_OK == 1
- R_OK||X_OK == 1
- the file we searched for had the x-bit set
-> access( file, R_OK||X_OK ) worked
- inicidentally, the file we searched for also had the r-bit set,
but we were not testing that in fact.
(transplanted from eebcaff6626f09af4f69b7b06f1246a06769d0af)

# Bare metal config options

config KERNEL_bare_metal

    select BARE_METAL

    help

      'Bare metal' refers to those programs that run without any kernel.

      You probably want to say 'y' here if you plan to use your compiler

      to build bootloaders. It is not yet suitable to build Linux kernels,

      though, because the APCI stuff relies on the target C library headers

      being available?!?!...