Merge remote-tracking branch 'stefanha/trivial-patches' into staging

# By Peter Crosthwaite (2) and others
# Via Stefan Hajnoczi
* stefanha/trivial-patches:
  xilinx_zynq: Cleanup ssi_create_slave
  petalogix_ml605_mmu: Cleanup ssi_create_slave()
  target-s390: Fix SRNMT
  linux-user: Don't omit comma for strace of rt_sigaction()
  test-visitor-serialization: Fix some memory leaks