libkms: return -EINVAL on fstat error

On error fstat return -1, instead return -EINVAL to caller

Signed-off-by: Maxime Villard <rustyBSD@gmx.fr>
Signed-off-by: Jerome Glisse <jglisse@redhat.com>

libkms/linux.c

@@ -68,7 +68,7 @@ linux_name_from_sysfs(int fd, char **out)
 
 	ret = fstat(fd, &buffer);
 	if (ret)
-		return ret;
+		return -EINVAL;
 
 	if (!S_ISCHR(buffer.st_mode))
 		return -EINVAL;