staging: hikey9xx: hi6421-spmi-pmic: cleanup probe code

Cleanup the error handling code, making the messages more
consistent and removing an uneeded call to free_irq().

While here, also remove debug messages and make the
error messages more consistent.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/651b4053599b9f25efecac3b1d4ce6abce0bd097.1611949675.git.mchehab+huawei@kernel.org


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>