gfs2: Don't remember delete unless it's successful

This patch changes function evict_unlinked_inode so it does not call
gfs2_inode_remember_delete until it gets a good return code from
gfs2_dinode_dealloc.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>