Added a call to libssh2_knownhost_writefile()

Updated to the slightly modified libssh2_knownhost_check() proto

example/simple/ssh2_exec.c

@@ -133,15 +133,18 @@ int main(int argc, char *argv[])
         return 2;
     }
 
+    /* read all hosts from here */
     libssh2_knownhost_readfile(nh, "known_hosts",
                                LIBSSH2_KNOWNHOST_FILE_OPENSSH);
 
+    /* store all known hosts to here */
+    libssh2_knownhost_writefile(nh, "dumpfile",
+                                LIBSSH2_KNOWNHOST_FILE_OPENSSH);
+
     fingerprint = libssh2_session_hostkey(session, &len);
     if(fingerprint) {
-        struct libssh2_knownhost host;
-        int check;
-
-        check = libssh2_knownhost_check(nh, (char *)hostname,
+        struct libssh2_knownhost *host;
+        int check = libssh2_knownhost_check(nh, (char *)hostname,
                                             (char *)fingerprint, len,
                                             LIBSSH2_KNOWNHOST_TYPE_PLAIN|
                                             LIBSSH2_KNOWNHOST_KEYENC_RAW,
@@ -149,7 +152,7 @@ int main(int argc, char *argv[])
 
         fprintf(stderr, "Host check: %d, key: %s\n", check,
                 (check <= LIBSSH2_KNOWNHOST_CHECK_MISMATCH)?
-                host.key:"<none>");
+                host->key:"<none>");
 
         /*****
          * At this point, we could verify that 'check' tells us the key is