avoid some clippy warnings

src/api2/node/syslog.rs

@@ -43,7 +43,7 @@ fn dump_journal(
                 Ok(line) => {
                     count += 1;
                     if count < start { continue };
-	            if limit <= 0 { continue };
+	            if limit == 0 { continue };
 
                     lines.push(json!({ "n": count, "t": line }));
 

src/api2/node/tasks.rs

@@ -75,7 +75,7 @@ fn read_task_log(
             Ok(line) => {
                 count += 1;
                 if count < start { continue };
-	        if limit <= 0 { continue };
+	        if limit == 0 { continue };
 
                 lines.push(json!({ "n": count, "t": line }));