s390/uaccess: remove extra blank line

In order to get uaccess.c (nearly) checkpatch warning free remove an
extra blank line:

CHECK: Blank lines aren't necessary before a close brace '}'
+
+}

Reviewed-by: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>