Update the comment & use the column position of the last formula record.

Change-Id: I877ec2153754328781e5d87b8eca47998b70fa22
(cherry picked from commit 5a295eb97b9461e603c723308135c1477846e839)
diff --git a/sc/source/filter/excel/impop.cxx b/sc/source/filter/excel/impop.cxx
index b60e62a..913d1ba 100644
--- a/sc/source/filter/excel/impop.cxx
+++ b/sc/source/filter/excel/impop.cxx
@@ -869,11 +869,9 @@ void ImportExcel::Shrfmla( void )

    OSL_ENSURE( pErgebnis, "+ImportExcel::Shrfmla(): ScTokenArray is NULL!" );

    // The range in this record can be erroneous especially the row range.
    // Use the row from the last FORMULA record as the start row.  The end row
    // will be adjusted by the formula cells that follow.
    SCCOL nCol1 = nFirstCol;
    SCCOL nCol2 = nLastCol;
    // The shared range in this record is erroneous more than half the time.
    // Don't ever rely on it.
    SCCOL nCol1 = mpLastFormula->mnCol;
    SCROW nRow1 = mpLastFormula->mnRow;

    ScAddress aPos(nCol1, nRow1, GetCurrScTab());