fix spelling in target sub directory

Cc: Richard Henderson <rth@twiddle.net>
Cc: Edgar E. Iglesias <edgar.iglesias@gmail.com>
Cc: Aurelien Jarno <aurelien@aurel32.net>
Cc: Alexander Graf <agraf@suse.de>
Cc: Aurelien Jarno <aurelien@aurel32.net>
Cc: Blue Swirl <blauwirbel@gmail.com>
Signed-off-by: Dong Xu Wang <wdongxu@linux.vnet.ibm.com>
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>