Use PRIx64 which defines the width correctly regardless or architecture.
Fixes build error:
rpmsg/rpmsg_sockif.c:610:57: error: format '%llx' expects argument of type 'long long unsigned int', but argument 4 has type 'uint64_t' {aka 'long unsigned int'} [-Werror=format=]
610 | snprintf(conn->nameid, sizeof(conn->nameid), ":%llx", g_rpmsg_id++);
| ~~~^ ~~~~~~~~~~~~
| | |
| | uint64_t {aka long unsigned int}
| long long unsigned int
| %lx
e163c74b90