Fix typo in doc.

redis/script.go

@@ -55,7 +55,7 @@ func (s *Script) args(spec string, keysAndArgs []interface{}) []interface{} {
 	return args
 }
 
-// Do evalutes the script. Under the covers, Do optimistically evaluates the
+// Do evaluates the script. Under the covers, Do optimistically evaluates the
 // script using the EVALSHA command. If the command fails because the script is
 // not loaded, then Do evaluates the script using the EVAL command (thus
 // causing the script to load).