Bug 1616780 - Add __NR_sched_getattr to the list of thread function r=jld

Introduced in:
8aeca4fa64

Shipping in glib 2.63.5 (available in Debian experimental)

Thanks to @padenot for the suggestion!

Differential Revision: https://phabricator.services.mozilla.com/D63451

--HG--
extra : moz-landing-system : lando

security/sandbox/linux/SandboxFilter.cpp

@@ -1160,6 +1160,7 @@ class ContentSandboxPolicy : public SandboxPolicyCommon {
 
       case __NR_getpriority:
       case __NR_setpriority:
+      case __NR_sched_getattr:
       case __NR_sched_get_priority_min:
       case __NR_sched_get_priority_max:
       case __NR_sched_getscheduler: