trivial: Style changed files

libethdrivers: Add missing header

With the latest lwIP sources, some of the SNMP-related definitions were
moved to a different header file. This commit adds in that missing
header file.

util_libs: remove autoconf.h from util_libs

this commit removes autoconf.h generation from each lib and
append '#include <<lib_name>/gen_config.h>' after each
'#include <autoconf.h>' since autoconf.h is only the for the
kernel config now. This is a temporarily solution, since we
currently don't have a way to tell which header files each file
is trying to include when it includes 'autoconf.h'

Added error control on return from initialize_free_bufs to fail if buffer cannot be created

fix licenses

Correctly drop the padding length after allocating

Use size portable types in print statements

Remove a debugging printf.

Fix for an allocation of buffer bug when not required, in lwip.c