sstatesig: Ensure we return all matches for find_sigdata

When the hashes to find isn't specified we need to return matches from both
the sstate cache and the local stamps directory regardless of how many we've
found so far. If we don't do this, we can miss stamps and the comparison is
less accurate/incorrect.

(From OE-Core rev: 08a074e11e2d517b81ca71fd9bda65297bb015a7)

(From OE-Core rev: 04fc682af7c1657b1c9f37b66a78c4ffc8066e24)

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

meta/lib/oe/sstatesig.py

@@ -128,7 +128,7 @@ def find_siginfo(pn, taskname, taskhashlist, d):
         else:
             filedates[fullpath] = os.stat(fullpath).st_mtime
 
-    if len(filedates) < 2 and not foundall:
+    if not taskhashlist or (len(filedates) < 2 and not foundall):
         # That didn't work, look in sstate-cache
         hashes = taskhashlist or ['*']
         localdata = bb.data.createCopy(d)