fix compiler warning
fix compiler warning

plugins/io/bsdio-inl.c:269:44: warning: logical ‘or’ of equal expressions [-Wlogical-op]
  269 |         } else if (last_err == EWOULDBLOCK || last_err == EAGAIN) {
      |                                            ^~

Change-Id: Id216e7429efd63ff25ffb66a5830c0820bbfd4d9
Reviewed-on: http://review.couchbase.org/c/libcouchbase/+/138672
Tested-by: Build Bot <80754af91bfb6d1073585b046fe0a474ce868509@couchbase.com>
Reviewed-by: Sergey Avseyev <87f6d5e4fd3644c3c20800cde7fd3ad1569370b3@gmail.com>

kojiromike/libcouchbase,couchbase/libcouchbase,couchbase/libcouchbase,couchbase/libcouchbase,couchbase/libcouchbase,kojiromike/libcouchbase,couchbase/libcouchbase,couchbase/libcouchbase,kojiromike/libcouchbase,couchbase/libcouchbase,kojiromike/libcouchbase