[hack] replace (char *)1 with constant
[hack] replace (char *)1 with constant

Summary: use the macro for `(char *)1` instead of literally `(char *)1`.

Reviewed By: alexchow

Differential Revision: D7944016

fbshipit-source-id: 37c00fa05a3efd0038a547add6d08f384d7863ea

jamesgpearce/flow,JonathanUsername/flow,nmote/flow,samwgoldman/flow,JonathanUsername/flow,AgentME/flow,mroch/flow,JonathanUsername/flow,jamesgpearce/flow,mroch/flow,facebook/flow,AgentME/flow,claudiopro/flow,gabelevi/flow,facebook/flow,popham/flow,gabelevi/flow,samwgoldman/flow,mroch/flow,mroch/flow,samwgoldman/flow,mroch/flow,gabelevi/flow,jamesgpearce/flow,gabelevi/flow,mroch/flow,nmote/flow,popham/flow,popham/flow,samwgoldman/flow,claudiopro/flow,gabelevi/flow,facebook/flow,nmote/flow,claudiopro/flow,samwgoldman/flow,popham/flow,jamesgpearce/flow,claudiopro/flow,AgentME/flow,facebook/flow,nmote/flow,JonathanUsername/flow,facebook/flow,JonathanUsername/flow,nmote/flow,popham/flow,JonathanUsername/flow,claudiopro/flow,jamesgpearce/flow,jamesgpearce/flow,facebook/flow,facebook/flow,nmote/flow,AgentME/flow,popham/flow,mroch/flow,gabelevi/flow,gabelevi/flow,AgentME/flow,jamesgpearce/flow,samwgoldman/flow,popham/flow,samwgoldman/flow,JonathanUsername/flow,nmote/flow