ACPI/IORT: Rework iort_match_node_callback() return value handling

ACPI/IORT: Rework iort_match_node_callback() return value handling

The return value handling in iort_match_node_callback() is
too convoluted; update the iort_match_node_callback() return
value handling to make code easier to read.

Signed-off-by: Hanjun Guo <[email protected]>
[[email protected]: rewrote commit log]
Signed-off-by: Lorenzo Pieralisi <[email protected]>
Tested-by: Ming Lei <[email protected]>
Tested-by: Wei Xu <[email protected]>
Tested-by: Sinan Kaya <[email protected]>
Cc: Lorenzo Pieralisi <[email protected]>
Cc: Tomasz Nowicki <[email protected]>