target-ppc: Check for error on address translation in memsave command

When we translate the virtual address to physical check for error.
Signed-off-by: NAneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: NAlexander Graf <agraf@suse.de>

cpus.c

@@ -1403,7 +1403,10 @@ void qmp_memsave(int64_t addr, int64_t size, const char *filename,
         l = sizeof(buf);
         if (l > size)
             l = size;
-        cpu_memory_rw_debug(cpu, addr, buf, l, 0);
+        if (cpu_memory_rw_debug(cpu, addr, buf, l, 0) != 0) {
+            error_setg(errp, "Invalid addr 0x%016" PRIx64 "specified", addr);
+            goto exit;
+        }
         if (fwrite(buf, 1, l, f) != l) {
             error_set(errp, QERR_IO_ERROR);
             goto exit;