crush: CrushWrapper::add_bucket - do not allow caller pass in null 'idout'

crush: CrushWrapper::add_bucket - do not allow caller pass in null 'idout'

*** Caught signal (Segmentation fault) **
 in thread 7f495c0f6300 thread_name:crushtool
 ceph version 12.1.2-768-gab69125 (ab6912523e779174f92f0b0fc10372bd0b645415) mimic (dev)
 1: (()+0x1a3d1) [0x7f495c1343d1]
 2: (()+0xf370) [0x7f4951deb370]
 3: (CrushWrapper::add_bucket(int, int, int, int, int, int*, int*, int*)+0x84) [0x7f49538ba084]
 4: (CrushCompiler::parse_bucket(__gnu_cxx::__normal_iterator<boost::spirit::tree_node<boost::spirit::node_val_data<char const*, boost::spirit::nil_t> >*, std::vector<boost::spirit::tree_node<boost::spirit::node_val_data<char const*, boost::spirit::nil_t> >, std::allocator<boost::spirit::tree_node<boost::spirit::node_val_data<char const*, boost::spirit::nil_t> > > > > const&)+0xef0) [0x7f49538dc170]
 5: (CrushCompiler::parse_crush(__gnu_cxx::__normal_iterator<boost::spirit::tree_node<boost::spirit::node_val_data<char const*, boost::spirit::nil_t> >*, std::vector<boost::spirit::tree_node<boost::spirit::node_val_data<char const*, boost::spirit::nil_t> >, std::allocator<boost::spirit::tree_node<boost::spirit::node_val_data<char const*, boost::spirit::nil_t> > > > > const&)+0x130) [0x7f49538dcba0]
 6: (CrushCompiler::compile(std::istream&, char const*)+0xb93) [0x7f49538deaa3]
 7: (main()+0x2615) [0x7f495c126015]
 8: (__libc_start_main()+0xf5) [0x7f49507ccb35]
 9: (()+0xf4b0) [0x7f495c1294b0]
2017-08-14 13:31:25.498050 7f495c0f6300 -1 *** Caught signal (Segmentation fault) **
 in thread 7f495c0f6300 thread_name:crushtool

Signed-off-by: xie xingguo <xie.xingguo@zte.com.cn>