Fixed warnings test_zipfile

Fixed implicit declaration of strcmp warning
Fixed switch case of enumeration not handled

Change-Id: Ic3f3690a2e749235b1b0dffd252b119855ad36c0
Author: Ariel Bernal <ariel.j.bernal@intel.com>
Reviewed-by: Tareq A Siraj <tareq.a.siraj@intel.com>

libzipfile/test_zipfile.c

@@ -1,5 +1,5 @@
 #include <zipfile/zipfile.h>
-
+#include <string.h>
 #include <stdio.h>
 #include <stdlib.h>
 
@@ -55,6 +55,8 @@ main(int argc, char** argv)
 
     switch (what)
     {
+        case HUH:
+            break;
         case LIST:
             dump_zipfile(stdout, zip);
             break;