ASoC: topology: fix memory leaks on sm, se and sbe

Currently when a kstrdup fails the error exit paths don't free
the allocations for sm, se and sbe.  This can be fixed by assigning
kc[i].private_value to these before doing the ksrtdup so that the error
exit path will be able to free these objects.

Addresses-Coverity: ("Resource leak")
Fixes: 9f90af3a

 ("ASoC: topology: Consolidate and fix asoc_tplg_dapm_widget_*_create flow")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Mark Brown <broonie@kernel.org>