[PATCH 0/3] musl fixes

[git at andred.net]

After having switched to musl as a c library, I noticed that
there are two versions of strerror_r()
  -> the POSIX version (implemented by musl and glibc)
  -> an incompatible GLIBC version (implemented by glibc only)

strerror_r() in general has been deprecated:
  http://austingroupbugs.net/view.php?id=655

libnl uses strerror_r(), which basically causes printf() of
*int* with *string format* specifiers on anything but glibc
  https://www.infradead.org/~tgr/libnl/
  git://git.infradead.org/users/tgr/libnl.git

In order to fix the musl problem, the attached series of patches
switches libnl over to using strerror_l() as recommended by
POSIX.

These patches apply on top of
commit b3dfa79
(nl-addr: avoid read-out-of-bound in nl_addr_fill_sockaddr())

Cheers,
Andre'