s390x: sclp: fix error handling for oversize control blocks

Requests over 4k are not a spec exception.
Signed-off-by: NJanosch Frank <frankja@linux.ibm.com>
Reviewed-by: NJason J. Herne <jjherne@linux.ibm.com>
Message-Id: <1569591203-15258-4-git-send-email-imbrenda@linux.ibm.com>
Acked-by: NDavid Hildenbrand <david@redhat.com>
Signed-off-by: NChristian Borntraeger <borntraeger@de.ibm.com>

hw/s390x/sclp.c

@@ -213,8 +213,7 @@ int sclp_service_call(CPUS390XState *env, uint64_t sccb, uint32_t code)
     cpu_physical_memory_read(sccb, &work_sccb, sccb_len);
 
     /* Valid sccb sizes */
-    if (be16_to_cpu(work_sccb.h.length) < sizeof(SCCBHeader) ||
-        be16_to_cpu(work_sccb.h.length) > SCCB_SIZE) {
+    if (be16_to_cpu(work_sccb.h.length) < sizeof(SCCBHeader)) {
         r = -PGM_SPECIFICATION;
         goto out;
     }