testing/newlib: Re-add libc_nano.a

Due to some invalid shell commands in the APKBUILD file, we stopped renaming the libc_nano and friends and thus missed those in our final package, effectively breaking the package's function.

So we stop doing bash substitution, and no longer rely on unsupported flags to read, making the line simpler to boot. Finally a period got shifted for some reason or another resulting that overal, we did not have our libraries any more.

Signed-off-by: Olliver Schinagl oliver@schinagl.nl