ceph: remove unneeded test in try_flush_caps

cap->session is always non-NULL, so we can just do a single test for
equality w/o testing explicitly for a NULL pointer.
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: "Yan, Zheng" <zyan@redhat.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>

fs/ceph/caps.c

@@ -2114,7 +2114,7 @@ static int try_flush_caps(struct inode *inode, u64 *ptid)
 		struct ceph_cap *cap = ci->i_auth_cap;
 		int delayed;
 
-		if (!session || session != cap->session) {
+		if (session != cap->session) {
 			spin_unlock(&ci->i_ceph_lock);
 			if (session)
 				mutex_unlock(&session->s_mutex);