[statsd] Fix a memory leak

Reported by the static analyzer:
frameworks/base/cmds/statsd/src/main.cpp:81:16: warning: Potential leak
of memory pointed to by 'data' [clang-analyzer-cplusplus.NewDeleteLeaks]

Bug: None
Test: Built with the static analyzer; warning disappeared.
Change-Id: Icf2cfb4bc4b397d8664e91ddb6c6e346c33ec4ac