efi_loader: initialize device path on alloc

Since the backing memory for a new device path can contain stale
data we have to make sure that we zero the buffer.  Otherwise some
code paths that don't set all fields in a structure backed by this
device path might contain unwanted stale data.

Signed-off-by: Patrick Wildt <patrick@blueri.se>
Reviewed-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Signed-off-by: Alexander Graf <agraf@suse.de>

lib/efi_loader/efi_device_path.c

@@ -66,6 +66,7 @@ static void *dp_alloc(size_t sz)
 		return NULL;
 	}
 
+	memset(buf, 0, sz);
 	return buf;
 }