tests: mmap2: ignore permission denied errors on /dev/mem
tests: mmap2: ignore permission denied errors on /dev/mem

Non-root users can't open /dev/mem, so it makes it hard to pass.
Ignore that case.

Signed-off-by: Mike Frysinger <8f3f75c74bd5184edcfa6534cab3c13a00a2f794@gentoo.org>

joel-porquet/tsar-uclibc,joel-porquet/tsar-uclibc,joel-porquet/tsar-uclibc,joel-porquet/tsar-uclibc