change streamAppendItem to use raxEOF instead of raxNext (#9138)
change streamAppendItem to use raxEOF instead of raxNext (#9138)

The call to raxNext didn't really progress in the rax, since we were already on the last item.
instead, all it does is check that it is indeed a valid item, so the new code clearer.
JackieXie168/redis,JackieXie168/redis,JackieXie168/redis,JackieXie168/redis