[skip ci]Fix allocator comment typo (#9363)

Signed-off-by: Ngodchen0212 <qingxiang.chen@zilliz.com>

internal/datanode/allocator.go

@@ -40,7 +40,7 @@ func newAllocator(s types.RootCoord) *allocator {
 	}
 }
 
-// allocID allocat one ID from rootCoord
+// allocID allocate one ID from rootCoord
 func (alloc *allocator) allocID() (UniqueID, error) {
 	ctx := context.TODO()
 	resp, err := alloc.rootCoord.AllocID(ctx, &rootcoordpb.AllocIDRequest{