Use comint-send-string

This one is solving the weird duplicating prompt issue. After the sanitation
patch we were sending newline twice.  Using comint-send-string because it is
more low-level and does not modify the input string, which we are building
correctly already (hopefully).

Author: arichiardi

inf-clojure.el

@@ -341,7 +341,7 @@ customizations."
   (let ((sanitized (inf-clojure--sanitize-command string)))
     (when (not (string-empty-p sanitized))
       (inf-clojure--log-string sanitized "----CMD->")
-      (comint-simple-send proc sanitized))))
+      (comint-send-string proc sanitized))))
 
 (defcustom inf-clojure-load-form "(clojure.core/load-file \"%s\")"
   "Format-string for building a Clojure expression to load a file.