perf tools: Add dso__data_get/put_fd()

perf tools: Add dso__data_get/put_fd()

Using dso__data_fd() in multi-thread environment is not safe since
returned fd can be closed and/or reused anytime.

So convert it to the dso__data_get/put_fd() pair to protect the access
with lock.

The original dso__data_fd() is deprecated and kept only for testing.

Signed-off-by: Namhyung Kim <[email protected]>
Acked-by: Adrian Hunter <[email protected]>
Cc: David Ahern <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>