Move find_mapping's log to its callsite

In the unwinder process we want to log if we can't find a mapping,
but in the tracers, we are just checking to see whether we should
send the event or not. Logging there is not really necessary and it
adds lots of noise.

src/bpf/profiler.bpf.c

@@ -331,9 +331,16 @@ int dwarf_unwind(struct bpf_perf_event_data *ctx) {
     LOG("\tcurrent bp: %llx", unwind_state->bp);
 
     mapping_t *mapping = find_mapping(per_process_id, unwind_state->ip);
+
     if (mapping == NULL) {
-      // find_mapping bumps the counters already.
-      // request_refresh_process_info?
+      LOG("[error] no mapping found for pc %llx", unwind_state->ip);
+      bump_unwind_error_mapping_not_found();
+      return 1;
+    }
+
+    if (unwind_state->ip < mapping->begin || unwind_state->ip >= mapping->end) {
+      LOG("[error] pc %llx not contained within begin: %llx end: %llx", unwind_state->ip, mapping->begin, mapping->end);
+      bump_unwind_error_mapping_does_not_contain_pc();
       return 1;
     }
 

src/bpf/shared_helpers.h

@@ -5,21 +5,7 @@ static __always_inline mapping_t* find_mapping(int per_process_id, u64 pc) {
   key.pid = __builtin_bswap32((u32) per_process_id);
   key.data = __builtin_bswap64(pc);
 
-  mapping_t *mapping = bpf_map_lookup_elem(&exec_mappings, &key);
-
-  if (mapping == NULL) {
-    LOG("[error] no mapping found for pc %llx", pc);
-    bump_unwind_error_mapping_not_found();
-    return NULL;
-  }
-
-  if (pc < mapping->begin || pc >= mapping->end) {
-    LOG("[error] pc %llx not contained within begin: %llx end: %llx", pc, mapping->begin, mapping->end);
-    bump_unwind_error_mapping_does_not_contain_pc();
-    return NULL;
-  }
-
-  return mapping;
+  return bpf_map_lookup_elem(&exec_mappings, &key);
 }
 
 static __always_inline bool process_is_known(int per_process_id) {