Fix the following problems when building with GCC 6 on i386:

  In file included from /«BUILDDIR»/psm/include/ipath_user.h:63:0,
                   from /«BUILDDIR»/psm/psm_user.h:45,
                   from am_reqrep_shmem.c:40:
  am_reqrep_shmem.c: In function 'psmi_shm_attach':
  /«BUILDDIR»/psm/include/ipath_udebug.h:79:28: error: format '%ld' expects argument of type 'long int', but argument 6 has type 'size_t {aka unsigned int}' [-Werror=format=]
      fprintf(__ipath_dbgout, "%s%s: " fmt, __ipath_mylabel, __func__, \
                              ^
  /«BUILDDIR»/psm/include/ipath_udebug.h:95:31: note: in expansion of macro '__IPATH_DBG_WHICH'
   #define _IPATH_PRDBG(fmt,...) __IPATH_DBG_WHICH(__IPATH_PROCDBG,fmt,##__VA_ARGS__)
                                 ^
  am_reqrep_shmem.c:544:2: note: in expansion of macro '_IPATH_PRDBG'
    _IPATH_PRDBG("Mapped and initialized shm object control page at %p,"
    ^