chore: move check for paste size

src/nvim/ops.c

@@ -2971,7 +2971,7 @@ void do_put(int regname, yankreg_T *reg, int dir, long count, int flags)
     y_array = reg->y_array;
   }
 
-  if (y_size > 0 && curbuf->terminal) {
+  if (curbuf->terminal) {
     terminal_paste(count, y_array, y_size);
     return;
   }

src/nvim/terminal.c

@@ -569,6 +569,9 @@ static bool is_filter_char(int c)
 
 void terminal_paste(long count, char_u **y_array, size_t y_size)
 {
+  if (y_size == 0) {
+    return;
+  }
   vterm_keyboard_start_paste(curbuf->terminal->vt);
   terminal_flush_output(curbuf->terminal);
   size_t buff_len = STRLEN(y_array[0]);