target: Have core_tmr_alloc_req() take an explicit GFP_xxx flag

Testing in_interrupt() to know when sleeping is allowed is not really
reliable (since eg it won't be true if the caller is holding a spinlock).
Instead have the caller tell core_tmr_alloc_req() what GFP_xxx to use;
every caller except tcm_qla2xxx can use GFP_KERNEL.

Signed-off-by: Roland Dreier <roland@purestorage.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

drivers/target/iscsi/iscsi_target_util.c

@@ -289,7 +289,8 @@ struct iscsi_cmd *iscsit_allocate_se_cmd_for_tmr(
 	}
 
 	se_cmd->se_tmr_req = core_tmr_alloc_req(se_cmd,
-				(void *)cmd->tmr_req, tcm_function);
+				(void *)cmd->tmr_req, tcm_function,
+				GFP_KERNEL);
 	if (!se_cmd->se_tmr_req)
 		goto out;