Summary:
glibc doesn't have a wrapper for gettid, leading this to this warning:

netconsblaster.c: In function ‘blaster_thread’:
netconsblaster.c:292:12: warning: implicit declaration of function ‘gettid’; did you mean ‘getgid’? [-Wimplicit-function-declaration]
  s->seed = gettid();
            ^~~~~~
            getgid

Call the syscall directly

Reviewed By: jof

Differential Revision: D32470141

fbshipit-source-id: c3d665a16e29042d5b68d0479dbe926b218db3a9