ASoC: fsl_mqs: Fix error handling in probe

ASoC: fsl_mqs: Fix error handling in probe

There are several problems in the error handling in fsl_mqs_probe().

1) "ret" isn't initialized on some paths.  GCC has a feature which
   warns about uninitialized variables but the code initializes "ret"
   to zero at the start of the function so the checking is turned off.
2) "gpr_np" is a pointer so initializing it to zero is confusing and
   generates a Sparse warning.
3) of_parse_phandle() doesn't return error pointers on error, it returns
   NULL.
4) If devm_snd_soc_register_component() fails then the function should
   free the "gpr_np".

Fixes: c76586c50fb7 ("ASoC: fsl_mqs: Add MQS component driver")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Link: https://lore.kernel.org/r/20191004102208.GB823@mwanda
Signed-off-by: Mark Brown <broonie@kernel.org>