perf pmu: fix duplicate conditional statement

perf pmu: fix duplicate conditional statement

Remove duplicate check for PERF_PMU_TYPE_DRM_END in perf_pmu__kind.

Fixes: f0feb21e0a10 ("perf pmu: Add PMU kind to simplify differentiating")
Signed-off-by: Anubhav Shelat <ashelat@redhat.com>
Reviewed-by: Ian Rogers <irogers@google.com>
Closes: https://lore.kernel.org/linux-perf-users/CA+G8Dh+wLx+FvjjoEkypqvXhbzWEQVpykovzrsHi2_eQjHkzQA@mail.gmail.com/
Signed-off-by: Namhyung Kim <namhyung@kernel.org>