staging: rtl8712: Use proper format in call to dev_err()

In the call to dev_err(), remove the cast of size_t to int
and change the format string accordingly.

As reported by the kernel test robot, the correct
format string for a size_t argument should be %zu.

Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Mauro Dreissig <mukadr@gmail.com>
Link: https://lore.kernel.org/r/20200705143552.9368-6-mukadr@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/rtl8712/hal_init.c

@@ -68,8 +68,8 @@ MODULE_FIRMWARE("rtlwifi/rtl8712u.bin");
 static u32 rtl871x_open_fw(struct _adapter *adapter, const u8 **mappedfw)
 {
 	if (adapter->fw->size > 200000) {
-		dev_err(&adapter->pnetdev->dev, "r8172u: Badfw->size of %d\n",
-			(int)adapter->fw->size);
+		dev_err(&adapter->pnetdev->dev, "r8712u: Bad fw->size of %zu\n",
+			adapter->fw->size);
 		return 0;
 	}
 	*mappedfw = adapter->fw->data;