IB/srp: Fix connection state tracking

Reception of a DREQ message only causes the state of a single
channel to change. Hence move the 'connected' member variable
from the target to the channel data structure. This patch
avoids that following false positive warning can be reported
by srp_destroy_qp():

WARNING: at drivers/infiniband/ulp/srp/ib_srp.c:617 srp_destroy_qp+0xa6/0x120 [ib_srp]()
Call Trace:
[<ffffffff8106e10f>] warn_slowpath_common+0x7f/0xc0
[<ffffffff8106e16a>] warn_slowpath_null+0x1a/0x20
[<ffffffffa0440226>] srp_destroy_qp+0xa6/0x120 [ib_srp]
[<ffffffffa0440322>] srp_free_ch_ib+0x82/0x1e0 [ib_srp]
[<ffffffffa044408b>] srp_create_target+0x7ab/0x998 [ib_srp]
[<ffffffff81346f60>] dev_attr_store+0x20/0x30
[<ffffffff811dd90f>] sysfs_write_file+0xef/0x170
[<ffffffff8116d248>] vfs_write+0xc8/0x190
[<ffffffff8116d411>] sys_write+0x51/0x90

Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Cc: Sagi Grimberg <sagig@mellanox.com>
Cc: Sebastian Parschauer <sebastian.riemer@profitbricks.com>
Cc: <stable@vger.kernel.org> #v3.19
Signed-off-by: Doug Ledford <dledford@redhat.com>
diff --git a/drivers/infiniband/ulp/srp/ib_srp.h b/drivers/infiniband/ulp/srp/ib_srp.h
index a611556..e690847 100644
--- a/drivers/infiniband/ulp/srp/ib_srp.h
+++ b/drivers/infiniband/ulp/srp/ib_srp.h
@@ -170,6 +170,7 @@
 
 	struct completion	tsk_mgmt_done;
 	u8			tsk_mgmt_status;
+	bool			connected;
 };
 
 /**
@@ -214,7 +215,6 @@
 	__be16			pkey;
 
 	u32			rq_tmo_jiffies;
-	bool			connected;
 
 	int			zero_req_lim;