The novelist behind the “Rambo” series is waging war — against his own creation. Author David Morrell, who breathed life into Vietnam War vet and one-man wrecking crew John Rambo in his 1972 novel “First Blood,” is the latest critic to badmouth Sylvester Stallone’s newest film. “I agree with these ‘Rambo: Last Blood’ reviews. This film is a mess, tweeted Morrell on Friday. “Embarrassed to have my name associated with it.” Morrell stated he had initially been involved in the creation of “Last Blood,” which was to show a more impassioned Rambo; instead, Matthew Cirulnick completed the gory screenplay. “I...