Remove a few unused functions reported by callcatcher (#11658)

Author: SmallJoker

src/chat.cpp

@@ -142,11 +142,6 @@ u32 ChatBuffer::getRows() const
 	return m_rows;
 }
 
-void ChatBuffer::scrollTop()
-{
-	m_scroll = getTopScrollPos();
-}
-
 void ChatBuffer::reformat(u32 cols, u32 rows)
 {
 	if (cols == 0 || rows == 0)

src/chat.h

@@ -110,8 +110,6 @@ class ChatBuffer
 	void scrollAbsolute(s32 scroll);
 	// Scroll to bottom of buffer (newest)
 	void scrollBottom();
-	// Scroll to top of buffer (oldest)
-	void scrollTop();
 
 	// Functions for keeping track of whether the lines were modified by any
 	// preceding operations