Fix leaks detected by clang scan-build (only 1 of 4 may be important though)

src/fio_engine.cpp

@@ -228,6 +228,7 @@ static enum fio_q_status bs_queue(struct thread_data *td, struct io_u *io)
         break;
     default:
         io->error = EINVAL;
+        delete op;
         return FIO_Q_COMPLETED;
     }
 

src/fio_sec_osd.cpp

@@ -284,6 +284,7 @@ static enum fio_q_status sec_queue(struct thread_data *td, struct io_u *io)
         break;
     default:
         io->error = EINVAL;
+        delete op_buf;
         return FIO_Q_COMPLETED;
     }
 

src/nbd_proxy.cpp

@@ -734,5 +734,6 @@ int main(int narg, const char *args[])
     exe_name = args[0];
     nbd_proxy *p = new nbd_proxy();
     p->exec(nbd_proxy::parse_args(narg, args));
+    delete p;
     return 0;
 }

src/osd_primary_chain.cpp

@@ -207,6 +207,7 @@ int osd_t::submit_bitmap_subops(osd_op_t *cur_op, pg_t & pg)
     std::vector<bitmap_request_t> *bitmap_requests = new std::vector<bitmap_request_t>();
     if (collect_bitmap_requests(cur_op, pg, *bitmap_requests) < 0)
     {
+        delete bitmap_requests;
         return -1;
     }
     op_data->n_subops = 0;

src/stub_osd.cpp

@@ -166,5 +166,4 @@ void run_stub(int peer_fd)
             break;
         }
     }
-    free(buf);
 }