perf bpf-filter: Return -ENOMEM directly when pfi allocation fails

Directly return -ENOMEM when pfi allocation fails,
instead of performing other operations on pfi.

Fixes: 0fe2b18ddc40 ("perf bpf-filter: Support multiple events properly")
Signed-off-by: Hao Ge <[e-mail]>
Acked-by: Namhyung Kim <[e-mail]>
Cc: [e-mail]
Cc: [e-mail]
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Namhyung Kim <[e-mail]>

tools/perf/util/bpf-filter.c

···
 	pfi = zalloc(sizeof(*pfi));
 	if (pfi == NULL) {
 		pr_err("Cannot save pinned filter index\n");
-		goto err;
+		return -ENOMEM;
 	}
 
 	pfi->evsel = evsel;