TTreeIndex::GetEntryNumberFriend don't call GetEntriesFast.

Calling GetEntriesFast is enough to know if you reach past the end (if we are in the last
file then it will return the precise number or something too large if we are far).
Calling GetEntries can move the cursor of the chain and thus change the state of the parent.

Author: pcanal

tree/treeplayer/src/TTreeIndex.cxx

@@ -345,7 +345,7 @@ Long64_t TTreeIndex::GetEntryNumberFriend(const TTree *parent)
    if (!parent) return -3;
    // We reached the end of the parent tree
    Long64_t pentry = parent->GetReadEntry();
-   if (pentry >= parent->GetEntries())
+   if (pentry >= parent->GetEntriesFast())
       return -2;
    GetMajorFormulaParent(parent);
    GetMinorFormulaParent(parent);