s390/cio: Refactor the routine that handles TIC CCWs

Extract the "does the target of this TIC already exist?" check from
ccwchain_handle_tic(), so that it's easier to refactor that function
into one that cp_init() is able to use.
Signed-off-by: Eric Farman <farman@linux.ibm.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Message-Id: <20190606202831.44135-3-farman@linux.ibm.com>
Signed-off-by: Cornelia Huck <cohuck@redhat.com>

drivers/s390/cio/vfio_ccw_cp.c

@@ -502,10 +502,6 @@ static int ccwchain_handle_tic(struct ccw1 *tic, struct channel_program *cp)
 	struct ccwchain *chain;
 	int len, ret;
 
-	/* May transfer to an existing chain. */
-	if (tic_target_chain_exists(tic, cp))
-		return 0;
-
 	/* Get chain length. */
 	len = ccwchain_calc_length(tic->cda, cp);
 	if (len < 0)
@@ -540,6 +536,10 @@ static int ccwchain_loop_tic(struct ccwchain *chain, struct channel_program *cp)
 		if (!ccw_is_tic(tic))
 			continue;
 
+		/* May transfer to an existing chain. */
+		if (tic_target_chain_exists(tic, cp))
+			continue;
+
 		ret = ccwchain_handle_tic(tic, cp);
 		if (ret)
 			return ret;