MFC r354664-r354666

r354664:
sesutil: fix an out-of-bounds array access

sesutil would allow the user to toggle an LED that was one past the maximum
element. If he tried, ENCIOC_GETELMSTAT would return EINVAL.

Reported by: Coverity
Coverity CID: 1398940
Sponsored by: Axcient

r354665:
sesutil: fix some memory leaks

Reported by: Coverity
Coverity CID: 1331665
Sponsored by: Axcient

r354666:
sesutil: fix another memory leak

Instead of calloc()ing (and forgetting to free) in a tight loop, just put
this small array on the stack.

Reported by: Coverity
Coverity CID: 1331665
Sponsored by: Axcient