Currently, the "failed to get handle for ..." log messages on attach are
a bit alarming and no context is provided. Print out that these are
retrieved when trying to match constraints and that such failures are
ignored, which should make administrators worry less.

While here, remove duplicated handle retrieving code in
acpi_spmc_check_constraints() because:

1. As is, it is dead code: We 'continue' if the handle is NULL, i.e., not already resolved, before trying to resolve it again.
2. This code is called after device suspension, which might make some objects disappear from the ACPI namespace. In any case, it seems unlikely that, suddenly, new objects would appear.