Check for return value from various snd_soc_dapm_* calls, as many of
them can return errors and this should be handled. Also, reintroduce
the allocation failure check for rt5645->eq_param as well. Make all
areas where return values are checked lead to the end of the function
in the case of an error. Finally, introduce a comment explaining how
resources here are actually eventually cleaned up by the caller.

Cc: Mark Brown <broonie@kernel.org>
Signed-off-by: Phillip Potter <phil@philpotter.co.uk>
Link: https://lore.kernel.org/r/20210503115736.2104747-56-gregkh@linuxfoundation.orgSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>