src: remove redundant symbol init in node_file.cc
src: remove redundant symbol init in node_file.cc

Don't lazy-init the oncomplete symbol string in the After() function,
it has already been created at module init time.

dreamllq/node,dreamllq/node,dreamllq/node,dreamllq/node,dreamllq/node,dreamllq/node,dreamllq/node,dreamllq/node,dreamllq/node