Use correct variable name for value to convert.
Use correct variable name for value to convert.

Note by @antirez: this code was never compiled because utils.c lacked the
float.h include, so we never noticed this variable was mispelled in the
past.

This should provide a noticeable speed boost when saving certain types
of databases with many sorted sets inside.

JackieXie168/redis,JackieXie168/redis,JackieXie168/redis,JackieXie168/redis