efi_loader: add missing EFI_CALL when closing a file

Closing the files uses the EFI protocol and specifically it's .close
callback.  This needs to be wrapped on an EFI_CALL()

Signed-off-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
Reviewed-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
diff --git a/lib/efi_loader/efi_file.c b/lib/efi_loader/efi_file.c
index b1495e5..d6dc823 100644
--- a/lib/efi_loader/efi_file.c
+++ b/lib/efi_loader/efi_file.c
@@ -1140,7 +1140,7 @@
 
 		if (!EFI_DP_TYPE(fp, MEDIA_DEVICE, FILE_PATH)) {
 			printf("bad file path!\n");
-			f->close(f);
+			EFI_CALL(f->close(f));
 			return NULL;
 		}