Make Whisper::Context#full and full_parallel return self

Author: KitaitiMakoto

bindings/ruby/ext/ruby_whisper_context.c

@@ -299,7 +299,7 @@ VALUE ruby_whisper_full(int argc, VALUE *argv, VALUE self)
   register_callbacks(rwp, &self);
   const int result = whisper_full(rw->context, rwp->params, c_samples, n_samples);
   if (0 == result) {
-    return Qnil;
+    return self;
   } else {
     rb_exc_raise(rb_funcall(eError, id_new, 1, result));
   }
@@ -390,7 +390,7 @@ ruby_whisper_full_parallel(int argc, VALUE *argv,VALUE self)
   register_callbacks(rwp, &self);
   const int result = whisper_full_parallel(rw->context, rwp->params, c_samples, n_samples, n_processors);
   if (0 == result) {
-    return Qnil;
+    return self;
   } else {
     rb_exc_raise(rb_funcall(eError, id_new, 1, result));
   }