fix(go.d/snmp): don't return error if no sysName (#18970)

src/go/plugin/go.d/modules/snmp/collect_sys_info.go

@@ -36,6 +36,7 @@ func (s *SNMP) getSysInfo() (*sysInfo, error) {
 	}
 
 	si := &sysInfo{
+		name:         "unknown",
 		organization: "Unknown",
 	}
 
@@ -67,10 +68,6 @@ func (s *SNMP) getSysInfo() (*sysInfo, error) {
 		}
 	}
 
-	if si.name == "" {
-		return nil, errors.New("no system name")
-	}
-
 	return si, nil
 }