buildroot

sane-backends: backport upstream commit to fix musl build

This commit adds a new patch to sane-backends, backported from upstream,
to fix the build with the musl C library.

Fixes:

  http://autobuild.buildroot.net/results/86c0d172f97a09230a1b589d599c54a656dae66d/

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