ASoC: topology: Remove unnecessary check for EOF

Caller already checks if hdr_pos is behind EOF, before calling
soc_tplg_valid_header(), so there is no need to recheck it again. This
also allows to remove behaviour of return 0 - forcing the caller to
break out of while loop.

Reviewed-by: Cezary Rojewski <cezary.rojewski@intel.com>
Reviewed-by: Ranjani Sridharan <ranjani.sridharan@linux.intel.com>
Signed-off-by: Amadeusz Sławiński <amadeuszx.slawinski@linux.intel.com>
Link: https://lore.kernel.org/r/20230127231111.937721-10-amadeuszx.slawinski@linux.intel.com


Signed-off-by: Mark Brown <broonie@kernel.org>