qemu_process: fix crash in qemuSaveImageDecompressionStart

Commit changing the code to allow passing NULL as @data into
qemuSaveImageDecompressionStart() was not correct as it left the
original call into the function as well.

Introduced-by: 2f3e582a1a
Fixes: https://bugzilla.redhat.com/show_bug.cgi?id=2247754
Signed-off-by: Pavel Hrdina <phrdina@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>

src/qemu/qemu_process.c

@@ -8208,9 +8208,6 @@ qemuProcessStartWithMemoryState(virConnectPtr conn,
         }
     }
 
-    if (qemuSaveImageDecompressionStart(data, fd, &intermediatefd, &errbuf, &cmd) < 0)
-        return -1;
-
     /* No cookie means libvirt which saved the domain was too old to mess up
      * the CPU definitions.
      */