perf evlist: Add success path to evlist__create_syswide_maps

perf evlist: Add success path to evlist__create_syswide_maps

Over various refactorings evlist__create_syswide_maps has been made to
only ever return with -ENOMEM. Fix this so that when
perf_evlist__set_maps is successfully called, 0 is returned.

Reviewed-by: Howard Chu <howardchu95@gmail.com>
Signed-off-by: Ian Rogers <irogers@google.com>
Reviewed-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Link: https://lore.kernel.org/r/20250228222308.626803-3-irogers@google.com
Fixes: 8c0498b6891d7ca5 ("perf evlist: Fix create_syswide_maps() not propagating maps")
Signed-off-by: Namhyung Kim <namhyung@kernel.org>