ASoC: soc-cache: dereferencing before checking

The patch c358e640

 "ASoC: soc-cache: Add trace event for
snd_soc_cache_sync()" introduced a dereference of "codec->cache_ops"
before we had checked it for NULL.

I pulled the check forward, and then pulled everything in an indent
level.

Signed-off-by: Dan Carpenter <error27@gmail.com>
Acked-by: Liam Girdwood <lrg@slimlogic.co.uk>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>