solve valgrind warning in child_info (#8505)
solve valgrind warning in child_info (#8505)

Valgrind warns about `write` accessing uninitialized memory, which was the struct padding.
yossigo/redis,ofirluzon/redis,antirez/redis,PKRoma/redis,ctripcorp/redis,charsyam/redis,antirez/redis,yossigo/redis,soloestoy/redis,ctripcorp/redis,oranagra/redis,ctripcorp/redis,PKRoma/redis,antirez/redis,charsyam/redis,ctripcorp/redis,PKRoma/redis,neomantra/redis,yossigo/redis,ofirluzon/redis,charsyam/redis,soloestoy/redis,antirez/redis,PKRoma/redis,charsyam/redis,ofirluzon/redis,soloestoy/redis,soloestoy/redis,neomantra/redis,soloestoy/redis,ofirluzon/redis,neomantra/redis,yossigo/redis,charsyam/redis,oranagra/redis,ofirluzon/redis,oranagra/redis,yossigo/redis,oranagra/redis,neomantra/redis,oranagra/redis,neomantra/redis,PKRoma/redis