ldd might be called for shell scrips during sysupgrade, causing it to
complain that they are not a dynamic executables.

This is a harmless error, so supress it to avoid confusing about them
being serious ones.

Signed-off-by: Jonas Gorski <jogo@openwrt.org>

git-svn-id: svn://svn.openwrt.org/openwrt/trunk@43315 3c298f89-4303-0410-b956-a3cf2f4a3e73