remove superfluous else block (#7620)
remove superfluous else block (#7620)

The else block would be executed when newlen == 0 and in the case memmove won't be called, so there's no need to set start.
yossigo/redis,ctripcorp/redis,ctripcorp/redis,charsyam/redis,charsyam/redis,soloestoy/redis,soloestoy/redis,oranagra/redis,yossigo/redis,neomantra/redis,antirez/redis,ctripcorp/redis,neomantra/redis,ofirluzon/redis,ofirluzon/redis,oranagra/redis,ofirluzon/redis,neomantra/redis,charsyam/redis,PKRoma/redis,charsyam/redis,soloestoy/redis,ofirluzon/redis,antirez/redis,ofirluzon/redis,antirez/redis,neomantra/redis,neomantra/redis,PKRoma/redis,yossigo/redis,yossigo/redis,PKRoma/redis,charsyam/redis,ctripcorp/redis,oranagra/redis,soloestoy/redis,yossigo/redis,oranagra/redis,oranagra/redis,antirez/redis,soloestoy/redis,PKRoma/redis,PKRoma/redis