examples: Avoid using uninitialized memory

Signed-off-by: Jakub Jelen <jjelen@redhat.com>
Reviewed-by: Norbert Pocs <norbertpocs0@gmail.com>

examples/senddata.c

@@ -8,7 +8,7 @@
 int main(void) {
   ssh_session session;
   ssh_channel channel;
-  char buffer[1024*1024];
+  char buffer[1024 * 1024] = {0};
   int rc;
   uint64_t total=0;
   uint64_t lastshown=4096;