efi: Avoid a memory leak in efi_bind_block() on error path

Free the memory used if an error occurs.

Series-to: u-boot
Series-cc: Matthew Garrett <mgarrett@aurora.tech>, efi
Cover-letter:
efi: Add docs and tests and a few tweaks
This series addresses feedback provided on the original series,
including:

- adding documentation and tests for the two new commands
- fixing an issue that somehow didn't fail in CI
- splitting up a large function into two parts
- using lmb for the allocation, instead of looking at internal tables
- dropping use of config.h

Link: https://lore.kernel.org/u-boot/20241123195616.305687-1-mjg59@srcf.ucam.org/
Link: https://patchwork.ozlabs.org/project/uboot/list/?series=433949&state=*&archive=both
END

Signed-off-by: Simon Glass <sjg@chromium.org>
Suggested-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
Signed-off-by: Simon Glass <sjg@chromium.org>

lib/efi_client/efi_app_init.c

@@ -60,8 +60,10 @@ int efi_bind_block(efi_handle_t handle, struct efi_block_io *blkio,
 	plat->handle = handle;
 	plat->blkio = blkio;
 	plat->device_path = malloc(device_path_len);
-	if (!plat->device_path)
+	if (!plat->device_path) {
+		free(plat);
 		return log_msg_ret("path", -ENOMEM);
+	}
 	memcpy(plat->device_path, device_path, device_path_len);
 
 	snprintf(name, sizeof(name), "efi_media_%x",