remove warning: ‘nIndex’ may be used uninitialized

Change-Id: I317c2f4409f556ab967e4f08caa99cffcfce26cc
Reviewed-on: https://gerrit.libreoffice.org/11876Reviewed-by: Kohei Yoshida <libreoffice@kohei.us>
Tested-by: Kohei Yoshida <libreoffice@kohei.us>

sc/source/core/data/compressedarray.cxx

@@ -241,7 +241,7 @@ template< typename A, typename D >
 void ScCompressedArray<A,D>::CopyFrom( const ScCompressedArray<A,D>& rArray, A nStart,
         A nEnd, long nSourceDy )
 {
-    size_t nIndex;
+    size_t nIndex = 0;
     A nRegionEnd;
     for (A j=nStart; j<=nEnd; ++j)
     {
@@ -373,7 +373,7 @@ void ScBitMaskCompressedArray<A,D>::CopyFromAnded(
         const ScBitMaskCompressedArray<A,D>& rArray, A nStart, A nEnd,
         const D& rValueToAnd, long nSourceDy )
 {
-    size_t nIndex;
+    size_t nIndex = 0;
     A nRegionEnd;
     for (A j=nStart; j<=nEnd; ++j)
     {