numa/numa01.sh: fixed errors under noncontinuous numa nodes list

The previous code numa01.sh thought all NUMA system had continuous
numa nodes list, and node id started from 0, but in fact it does not.

There are lots of system contains noncontinuous numa nodes list
 e.g:
 # numactl --hardware
 available: 4 nodes (0,2,4,7)
 node 0 cpus: 0 4 8 12 16 20 24 28
 node 0 size: 4061 MB
 node 0 free: 3756 MB
 node 2 cpus: 1 5 9 13 17 21 25 29
 node 2 size: 4096 MB
 node 2 free: 3196 MB
 node 4 cpus: 2 6 10 14 18 22 26 30
 node 4 size: 4096 MB
 node 4 free: 3885 MB
 node 7 cpus: 3 7 11 15 19 23 27 31
 node 7 size: 4095 MB
 node 7 free: 3947 MB
 node distances:
 node   0   2   4   7
   0:  10  20  20  20
   2:  20  10  20  20
   4:  20  20  10  20
   7:  20  20  20  10

in such discontinuous nodes system, numa01.sh would fail with
such error log:
 libnuma: Warning: node argument 1 is out of range

The patch fixed it, and removed some useless/redundancy val/func,
such as 'max_node' val and 'getmax' func, also make some cleanup.

Signed-off-by: Zhouping Liu <zliu@redhat.com>
Acked-by: Wanlong Gao <gaowanlong@cn.fujitsu.com>
Signed-off-by: Wanlong Gao <gaowanlong@cn.fujitsu.com>