fix comments spelling (#6829)

Signed-off-by: Zhou Hao <zhouhao@cn.fujitsu.com>

promql/engine_test.go

@@ -1154,7 +1154,7 @@ func TestQueryLogger_basic(t *testing.T) {
 		testutil.Ok(t, res.Err)
 	}
 
-	// Query works without query log initalized.
+	// Query works without query log initialized.
 	queryExec()
 
 	f1 := NewFakeQueryLogger()

tsdb/db.go

@@ -91,7 +91,7 @@ type Options struct {
 	// WALCompression will turn on Snappy compression for records on the WAL.
 	WALCompression bool
 
-	// StripeSize is the size in entries of the series hash map. Reducing the size will save memory but impact perfomance.
+	// StripeSize is the size in entries of the series hash map. Reducing the size will save memory but impact performance.
 	StripeSize int
 }