PCI: ibmphp: Fix double unmap of io_mem

PCI: ibmphp: Fix double unmap of io_mem

BugLink: https://bugs.launchpad.net/bugs/1948873
[ Upstream commit faa2e05ad0dccf37f995bcfbb8d1980d66c02c11 ]

ebda_rsrc_controller() calls iounmap(io_mem) on the error path. Its caller,
ibmphp_access_ebda(), also calls iounmap(io_mem) on good and error paths.

Remove the iounmap(io_mem) invocation from ebda_rsrc_controller().

[bhelgaas: remove item from TODO]
Link: https://lore.kernel.org/r/20210818165751.591185-1-os.vaslot@gmail.com
Signed-off-by: Vishal Aslot <os.vaslot@gmail.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
Signed-off-by: Kelsey Skunberg <kelsey.skunberg@canonical.com>