Removing the duplicate copy of char_to_byte_length_safe().

It appeared during a merge from 10.2 to bb-10.2-ext.

sql/item.h

@@ -96,13 +96,6 @@ enum precedence {
 
 typedef Bounds_checked_array<Item*> Ref_ptr_array;
 
-static inline uint32
-char_to_byte_length_safe(size_t char_length_arg, uint32 mbmaxlen_arg)
-{
-  ulonglong tmp= ((ulonglong) char_length_arg) * mbmaxlen_arg;
-  return tmp > UINT_MAX32 ? UINT_MAX32 : static_cast<uint32>(tmp);
-}
-
 bool mark_unsupported_function(const char *where, void *store, uint result);
 
 /* convenience helper for mark_unsupported_function() above */

sql/sql_type.h

@@ -184,10 +184,10 @@ class DTCollation {
 
 
 static inline uint32
-char_to_byte_length_safe(uint32 char_length_arg, uint32 mbmaxlen_arg)
+char_to_byte_length_safe(size_t char_length_arg, uint32 mbmaxlen_arg)
 {
   ulonglong tmp= ((ulonglong) char_length_arg) * mbmaxlen_arg;
-   return (tmp > UINT_MAX32) ? (uint32) UINT_MAX32 : (uint32) tmp;
+  return tmp > UINT_MAX32 ? UINT_MAX32 : static_cast<uint32>(tmp);
 }
 
 /**