Bug 240665 Can't navigate through some page lines using left or right arrow

r=aaronleventhal, sr=henry.jia
Patch by ginn.chen@sun.com

layout/generic/nsFrame.cpp

@@ -3630,6 +3630,7 @@ nsFrame::PeekOffset(nsIPresContext* aPresContext, nsPeekOffsetStruct *aPos)
               aPos->mContentOffset = newOffset +1;
             else
               aPos->mContentOffset = newOffset;//to beginning of frame
+            return NS_OK;
           }
         }
       }

layout/html/base/src/nsFrame.cpp

@@ -3630,6 +3630,7 @@ nsFrame::PeekOffset(nsIPresContext* aPresContext, nsPeekOffsetStruct *aPos)
               aPos->mContentOffset = newOffset +1;
             else
               aPos->mContentOffset = newOffset;//to beginning of frame
+            return NS_OK;
           }
         }
       }