After-merge fix for bug#14151.

sql/sql_partition.cc:
  After-merge fix for bug#14151:
  This use of "md5.h" is new in 5.1 and must be changed to "my_md5.h" as well.

sql/sql_partition.cc

@@ -36,7 +36,7 @@
 #include "mysql_priv.h"
 #include <errno.h>
 #include <m_ctype.h>
-#include "md5.h"
+#include "my_md5.h"
 
 #ifdef WITH_PARTITION_STORAGE_ENGINE
 #include "ha_partition.h"