If the struct mmc_pwrseq_match .alloc function used to allocate a
struct mmc_pwrseq fails, the error is propagated to mmc_of_parse().
But instead of returning the error code in pwrseq, host->pwrseq is
returned which will always be 0. So mmc_of_parse() succeeds even if
the pwrseq .alloc function failed and host->pwrseq is NULL.
This makes the SDIO device to not be powered if the power sequencing
.alloc functions wants to be deferred due a missing resource because
the mmc controller driver probe did wrongly succeed.
Fixes: 0f12a0ce4ce4a ("mmc: pwrseq: simplify alloc/free hooks")
Signed-off-by: Javier Martinez Canillas <javier.martinez@xxxxxxxxxxxxxxx>