sstate: Normalise paths before comparing with the whitelist

Without this, path components like // could break comparisions with the whitelist leading
to warnings being displayed to the user unintentionally.

(From OE-Core rev: d3c46ca56fab2f07bf16b61514f30765543a8747)

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

meta/classes/sstate.bbclass

@@ -150,6 +150,7 @@ def sstate_install(ss, d):
     match = []
     for f in sharedfiles:
         if os.path.exists(f):
+            f = os.path.normpath(f)
             realmatch = True
             for w in whitelist:
                 if f.startswith(w):