Categorize engine and profile options

Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff --git a/engines/libaio.c b/engines/libaio.c
index 4d1f3a3..0dca583 100644
--- a/engines/libaio.c
+++ b/engines/libaio.c
@@ -32,6 +32,8 @@
 		.type	= FIO_OPT_STR_SET,
 		.off1	= offsetof(struct libaio_options, userspace_reap),
 		.help	= "Use alternative user-space reap implementation",
+		.category = FIO_OPT_C_ENGINE,
+		.category = FIO_OPT_G_LIBAIO,
 	},
 	{
 		.name	= NULL,