Remove an unused function

rec_offs_nth_extern_old() was introduced in
commit a4948da
and never used.

storage/innobase/include/rem0rec.h

@@ -642,17 +642,6 @@ rec_offs_any_null_extern(
 	const ulint*	offsets)	/*!< in: rec_get_offsets(rec) */
 	MY_ATTRIBUTE((warn_unused_result));
 
-/******************************************************//**
-Returns nonzero if the extern bit is set in nth field of rec.
-@return nonzero if externally stored */
-UNIV_INLINE
-ulint
-rec_offs_nth_extern_old(
-/*================*/
-	const rec_t*	rec,	/*!< in: record */
-	ulint		    n	/*!< in: index of the field */)
-	MY_ATTRIBUTE((warn_unused_result));
-
 /** Mark the nth field as externally stored.
 @param[in]	offsets		array returned by rec_get_offsets()
 @param[in]	n		nth field */

storage/innobase/include/rem0rec.ic

@@ -955,21 +955,6 @@ rec_offs_any_null_extern(
 	return(NULL);
 }
 
-/******************************************************//**
-Returns nonzero if the extern bit is set in nth field of rec.
-@return nonzero if externally stored */
-UNIV_INLINE
-ulint
-rec_offs_nth_extern_old(
-/*================*/
-	const rec_t*	rec,	/*!< in: record */
-	ulint		    n	/*!< in: index of the field */)
-{
-	if(rec_get_1byte_offs_flag(rec))
-		return 0;
-	return (rec_2_get_field_end_info(rec,n) & REC_2BYTE_EXTERN_MASK);
-}
-
 /******************************************************//**
 Gets the physical size of a field.
 @return length of field */