MFC r333307 (by sbruno):

MFC r333307 (by sbruno):
Cleanup sundry clang warnings for code that is not upstream in illumos.
https://github.com/illumos/illumos-gate/edit/master/usr/src/lib/libzfs/common/libzfs_sendrecv.c

Patch our version of it to quiesce warnings until someone decides to sync
up our code:

libzfs_sendrecv.c:2555:30: warning: format specifies type 'unsigned long'
  but the argument has type 'uint64_t' (aka 'unsigned long long') [-Wformat]
                                sprintf(guidname, "%lu", thisguid);
                                                   ~~~   ^~~~~~~~
                                                   %llu
libzfs_sendrecv.c:2612:29: warning: format specifies type 'unsigned long'
  but the argument has type 'uint64_t' (aka 'unsigned long long') [-Wformat]
                        sprintf(guidname, "%lu", parent_fromsnap_guid);
                                           ~~~   ^~~~~~~~~~~~~~~~~~~~
                                           %llu
libzfs_sendrecv.c:2645:29: warning: format specifies type 'unsigned long'
  but the argument has type 'uint64_t' (aka 'unsigned long long') [-Wformat]
                        sprintf(guidname, "%lu", parent_fromsnap_guid);
                                           ~~~   ^~~~~~~~~~~~~~~~~~~~
                                           %llu