xfsprogs: bump to 4.16.1

xfsprogs: bump to 4.16.1

Resolves build failures like:
http://autobuild.buildroot.net/results/953/95307f0f56c7ead1bd1f0ab0049aeb8b30fdc11c/

libunistring to libicu conversion required modifications to
0001-mdrestore-do-not-do-dynamic-linking-of-libtool-libra.patch and
the libicu usage doesn't require the
0005-xfs_scrub-fix-cross-compile-with-libunistring.patch patch. I
verified that the configuration time setup of the LIBICU library
works correctly and doesn't require us to remove it.

Upstream has reworked/included the following:
0003-workqueue-add-missing-pthreads-header.patch
0004-xfs_scrub-add-missing-paths-header.patch
0006-xfs_scrub-fix-build-with-older-kernel-headers.patch

Signed-off-by: Matthew Weber <matthew.weber@rockwellcollins.com>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>