perf unwind: Fix map reference counts

The result of thread__find_map is the map in the passed in
addr_location. Calling addr_location__exit puts that map and so copies
need to do a map__get. Add in the corresponding map__puts.

v2. Add missing map__put when dso is missing.

Signed-off-by: Ian Rogers <irogers@google.com>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Ivan Babrou <ivan@cloudflare.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Link: https://lore.kernel.org/r/20230623043107.4077510-1-irogers@google.com


Signed-off-by: Namhyung Kim <namhyung@kernel.org>