misc: rtsx: Fix memory leak in rtsx_pci_probe

When mfd_add_devices() fail, pcr->slots should also be freed. However,
the current implementation does not free the member, leading to a memory
leak.

Fix this by adding a new goto label that frees pcr->slots.

Signed-off-by: Keita Suzuki <keitasuzuki.park@sslab.ics.keio.ac.jp>
Link: https://lore.kernel.org/r/20200909071853.4053-1-keitasuzuki.park@sslab.ics.keio.ac.jp


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