Bug 22391925: INNODB: FIX UNNECESSARY TYPE CASTS IN I_S.CC

mysql-5.7 cleanup changes suggested by Marko

Calls to Field_longlong::store() using a ulint should use version
store(longlong nr, bool unsigned_val)   instead of store(double nr)
in order to avoid conversion to a double and back.

Previously approved for mysql-trunk in rb#11021

Author: kdjakevin