pvs-studio: V1001 variable assigned but is not used by the end of the function

Change-Id: Ida759ae9fce3d384b19e41683bdcd796eb158efe
Reviewed-on: https://gerrit.libreoffice.org/62147
Tested-by: Jenkins
Reviewed-by: Caolán McNamara <caolanm@redhat.com>
Tested-by: Caolán McNamara <caolanm@redhat.com>

sc/source/core/data/markdata.cxx

@@ -500,7 +500,7 @@ std::vector<sc::ColRowSpan> ScMarkData::GetMarkedColSpans() const
             while(false);
 
             // Merge marked.
-            itPos = aSpans.insert(itPos, aMarkRange.aStart.Col(), aMarkRange.aEnd.Col()+1, true).first;
+            aSpans.insert(itPos, aMarkRange.aStart.Col(), aMarkRange.aEnd.Col()+1, true);
 
             return sc::toSpanArray<SCCOLROW,sc::ColRowSpan>(aSpans);
         }