stdlib: random_r: fix unaligned access in initstate and initstate_r [BZ #30584]

stdlib: random_r: fix unaligned access in initstate and initstate_r [BZ #30584]

The initstate{,_r} interfaces are documented in BSD as needing an aligned
array of 32-bit values, but neither POSIX nor glibc's own documentation
require it to be aligned. glibc's documentation says it "should" be a power
of 2, but not must.

Use memcpy to read and write to `state` to handle such an unaligned
argument.

Co-authored-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
Reviewed-by: Florian Weimer <fweimer@redhat.com>