MdePkg: BaseOrderedCollectionRedBlackTreeLib: silence invalid gcc warning

Gcc-4.4 reports the following build failure:

  BaseOrderedCollectionRedBlackTreeLib.c:
    In function 'OrderedCollectionInsert':
  BaseOrderedCollectionRedBlackTreeLib.c:586:
    error: 'Result' may be used uninitialized in this function

This is incorrect. There are two areas of use of Result to consider:

- In the very first while loop. The warning is likely not about this code
  area, because Result is assigned directly before use.

- The last use of Result in the function. The build warning / error is
  incorrect. For Result to be uninitialized at that point, the very first
  while loop must not have been entered at all (because that loop assigns
  a value to Result). However, if that loop is never entered, then Parent
  is still NULL. And Parent==NULL implies that the use of Result is never
  reached, because we jump to the Done label just before it.

Assign an irrelevant value of 0 to Result at the beginning of the function
in order to silence the incorrect warning.

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Jordan Justen <jordan.l.justen@intel.com>

git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@15812 6f19259b-4bc3-4df7-8a09-765794883524

MdePkg/Library/BaseOrderedCollectionRedBlackTreeLib/BaseOrderedCollectionRedBlackTreeLib.c

@@ -589,6 +589,7 @@ OrderedCollectionInsert (
 
   Tmp = Tree->Root;
   Parent = NULL;
+  Result = 0;
 
   //
   // First look for a collision, saving the last examined node for the case