bitbake: siggen: Clean up task reference formats

Currently siggen uses the format "<filename>.<taskname>" for referencing tasks
whilst runqueue uses "<filename>:<taskname>". This converts to use ":" as the
separator everywhere.

This is an API breaking change since the cache is affected, as are siginfo files
and any custom signature handlers such as those in OE-Core.

Ultimately this will let us clean up and the accessor functions from runqueue,
removing all the ".rsplit(".", 1)[0]" type code currently all over the place.
Once a standard is used everwhere we can update the code over time to be more
optimal.

(Bitbake rev: 07e539e1c566ca3434901e1a00335cb76c69d496)

Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

bitbake/lib/bb/data.py

@@ -422,7 +422,7 @@ def generate_dependency_hash(tasklist, gendeps, lookupcache, whitelist, fn):
             var = lookupcache[dep]
             if var is not None:
                 data = data + str(var)
-        k = fn + "." + task
+        k = fn + ":" + task
         basehash[k] = hashlib.sha256(data.encode("utf-8")).hexdigest()
         taskdeps[task] = alldeps