Currently we parallel process the files we install running dwarfsrcfiles over
each one in parallel threads but requiring a lock to write the results to one
file. This is not ideal for performance and means we can't then use per file
data for other purposes such as source code license processing.
Rework the code so that the list of source files is generated per installed
file and is reusable.
The code still generates a null separated debugsources.list file since this
is used by a shell pipeline but it no longer needs locking.
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
