perf/bpf: Change the !CONFIG_BPF_SYSCALL stubs to static inlines

Otherwise the compiler will be unhappy if they go unused,
which they do on allnoconfigs.

Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Kyle Huey <me@kylehuey.com>
Link: https://lore.kernel.org/r/ZhkE9F4dyfR2dH2D@gmail.com

Author: ingomolnar

kernel/events/core.c

@@ -9638,21 +9638,21 @@ static void perf_event_free_bpf_handler(struct perf_event *event)
 	bpf_prog_put(prog);
 }
 #else
-static int bpf_overflow_handler(struct perf_event *event,
-				struct perf_sample_data *data,
-				struct pt_regs *regs)
+static inline int bpf_overflow_handler(struct perf_event *event,
+				       struct perf_sample_data *data,
+				       struct pt_regs *regs)
 {
 	return 1;
 }
 
-static int perf_event_set_bpf_handler(struct perf_event *event,
-				      struct bpf_prog *prog,
-				      u64 bpf_cookie)
+static inline int perf_event_set_bpf_handler(struct perf_event *event,
+					     struct bpf_prog *prog,
+					     u64 bpf_cookie)
 {
 	return -EOPNOTSUPP;
 }
 
-static void perf_event_free_bpf_handler(struct perf_event *event)
+static inline void perf_event_free_bpf_handler(struct perf_event *event)
 {
 }
 #endif