tracing: Revert commits improving handling of saved_tgids

This reverts commit 7005c6ee ("tracing: Free saved_tgids memory
in free_saved_cmdlines_buffer") and commit be0b454d ("tracing:
Modify saved_tgids size for change in saved_cmdline_size")

An upstream patch is now available that does the same thing and
handles additional cases as well.

Change-Id: I05cf2dc566a6425e58076ae2e9698335b6d738cc
Signed-off-by: Dennis Cagle <dcagle@codeaurora.org>