ASoC: intel/sdw_utils: Assign initial value in asoc_sdw_rt_amp_spk_rtd_init()

ASoC: intel/sdw_utils: Assign initial value in asoc_sdw_rt_amp_spk_rtd_init()

Initialize "ret" with "-EINVAL" to handle cases where "strstr()" for
"codec_dai->component->name_prefix" doesn't find "-1" nor "-2". In that
case "name_prefix" is invalid because for current implementation it's
expected to have either "-1" or "-2" in it. (Maybe "-3", "-4" and so on
in the future.)

Link: https://scan5.scan.coverity.com/#/project-view/36179/10063?selectedIssue=1627120
Signed-off-by: I Hsin Cheng <richard120310@gmail.com>
Link: https://patch.msgid.link/20250505185423.680608-1-richard120310@gmail.com
Signed-off-by: Mark Brown <broonie@kernel.org>