update schkernel_mec_defconfig
Revert "warning: operation on 'ret' may be undefined [-Wsequence-point]"

This reverts commit d6720858db731cd3b916a5373f85bde58e8164de.
Fix compile warnings

Signed-off-by: flar2 <asegaert@gmail.com>
fix compilation warnings
update buildkernel scripts