sysklogd: fix build on musl

sysklogd: fix build on musl

This commit add a stack of small patches that make sysklogd build fine
with the musl C library. Build with uClibc and glibc has been tested
with those patches applied as well.

The first patch is slightly rework (better description and capital
letter to the title) in preparation for upstream submission.

Fixes:

  http://autobuild.buildroot.net/results/8fa2bf73f983330884bce2e5ac31e01dee112ba9/

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>