dlm: fix srcu_read_lock() return type to int

[ Upstream commit 57cdd1a1 ]

The return type of srcu_read_lock() is int and not bool. Whereas we
using the ret variable only to evaluate a bool type of
dlm_lowcomms_con_has_addr() to check if an address is already being set.

Fixes: 6f0b0b5d ("fs: dlm: remove dlm_node_addrs lookup list")
Signed-off-by: Alexander Aring <aahringo@redhat.com>
Signed-off-by: David Teigland <teigland@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>