porting: extattr_remove_fd() doesn't exist

Fix typo extattr_remove_fd() --> extattr_delete_fd()

Change-Id: I0dc3399722eb272d3c04836726e22b212ef15eba
BUG: 1111774
Signed-off-by: Harshavardhana <harsha@harshavardhana.net>
Reviewed-on: http://review.gluster.org/8335
Tested-by: Gluster Build System <jenkins@build.gluster.com>