The aerdriver.nosourceid kernel parameter was intended for working around
broken chipsets don't supply the source ID for AER events. We recently
added PCI_BUS_FLAGS_NO_AERSID, which can be set by quirks for the same
purpose.
Remove the aerdriver.nosourceid kernel parameter. For anything other than
debugging, asking users to find and use kernel parameters is a poor user
experience. Instead, we should add PCI_BUS_FLAGS_NO_AERSID quirks for any
hardware that needs it.