Bug 1050035 (part 2) - Remove the fallible version of PL_DHashTableInit(). r=froydnj,mrbkap.

Because it's no longer needed now that entry storage isn't allocated there.
(The other possible causes of failures are much less interesting and simply
crashing is a reasonable thing to do for them.)

This also makes PL_DNewHashTable() infallible.

netwerk/cache/nsCacheService.cpp

@@ -1155,8 +1155,7 @@ nsCacheService::Init()
     }
 
     // initialize hashtable for active cache entries
-    rv = mActiveEntries.Init();
-    if (NS_FAILED(rv)) return rv;
+    mActiveEntries.Init();
 
     // create profile/preference observer
     if (!mObserver) {