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.

source "config/backend.in"

source "config/global.in"

source "config/target.in"

source "config/toolchain.in"

source "config/kernel.in"

source "config/binutils.in"

source "config/cc.in"

source "config/libc.in"

source "config/debug.in"

source "config/companion_libs.in"

source "config/companion_tools.in"

source "config/test_suite.in"