ASoC: dapm: Fix a couple uninitialized ret variables

Smatch complains that these variables could be uninitialized.  The first
one in snd_soc_dai_link_event() is probably a false positive, because
probably we know the lists are not empty.  I would normally ignore the
warning, but GCC complains here as well so I just silenced the warning.
The "ret" in snd_soc_dapm_new_dai() does need to be initialized or it
leads to a bogus dereference in the caller.

Fixes: 3bbf5d34 ("ASoC: dapm: Move error handling to snd_soc_dapm_new_control_unlocked")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Mark Brown <broonie@kernel.org>