perf/core: Fix !CONFIG_PERF_EVENTS build warnings and failures
sparc64 runs into this warning:
include/linux/security.h:1913:52: warning: 'struct perf_event' declared inside parameter list will not be visible outside of this definition or declaration
which is escalated to a build error in some of the .c files due to -Werror.
Fix it via a forward declaration, like we do for perf_event_attr, the stub inlines
don't actually need to know the structure of this struct.
Fixes: da97e18458fb: ("perf_event: Add support for LSM and SELinux checks") Cc: "Joel Fernandes (Google)" <joel@joelfernandes.org> Cc: linux-kernel@vger.kernel.org Cc: Peter Zijlstra <peterz@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Namhyung Kim <namhyung@kernel.org> Signed-off-by: Ingo Molnar <mingo@kernel.org>