s390/lcs: fix variable dereferenced before check

smatch complains about
drivers/s390/net/lcs.c:1741 lcs_get_control() warn: variable dereferenced before check 'card->dev' (see line 1739)

Fixes: 27eb5ac8

 ("[PATCH] s390: lcs driver bug fixes and improvements [1/2]")
Signed-off-by: Alexandra Winter <wintera@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>