efi_driver: simplify efi_uc_stop(), call efi_free_pool()

We have exported efi_free_pool(). There is no need to use EFI_CALL().

Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
diff --git a/lib/efi_driver/efi_uclass.c b/lib/efi_driver/efi_uclass.c
index 5a285aa..aabee0e 100644
--- a/lib/efi_driver/efi_uclass.c
+++ b/lib/efi_driver/efi_uclass.c
@@ -246,7 +246,7 @@
 				goto out;
 		}
 	}
-	ret = EFI_CALL(systab.boottime->free_pool(entry_buffer));
+	ret = efi_free_pool(entry_buffer);
 	if (ret != EFI_SUCCESS)
 		log_err("Cannot free EFI memory pool\n");