net/iucv: fix indentation in __iucv_message_receive()

smatch complains about
net/iucv/iucv.c:1119 __iucv_message_receive() warn: inconsistent indenting

While touching this line, also make the return logic consistent and thus
get rid of a goto label.

Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com>
Reviewed-by: Karsten Graul <kgraul@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>