Added complementary blobmsg_close_table() before returning from function
on error.

Signed-off-by: Sławomir Demeszko <s.demeszko@wireless-instruments.com>

git-svn-id: svn://svn.openwrt.org/openwrt/trunk@43477 3c298f89-4303-0410-b956-a3cf2f4a3e73