Allow SYS_sched_getparam and SYS_sched_getscheduler
musl uses them for pthread_getschedparam()

source: https://git.alpinelinux.org/aports/commit/community/chromium?id=54af9f8ac24f52d382c5758e2445bf0206eff40e

--- qtwebengine/src/3rdparty/chromium/services/service_manager/sandbox/linux/bpf_renderer_policy_linux.cc	2019-11-12 20:48:20.013724661 +0100
+++ qtwebengine/src/3rdparty/chromium/services/service_manager/sandbox/linux/bpf_renderer_policy_linux.cc.patched	2019-11-12 20:58:57.330695676 +0100
@@ -93,10 +93,16 @@
     case __NR_sysinfo:
     case __NR_times:
     case __NR_uname:
+#if !defined(__GLIBC__)
+    case __NR_sched_getparam:
+    case __NR_sched_getscheduler:
+#endif
       return Allow();
     case __NR_sched_getaffinity:
+#if defined(__GLIBC__)
     case __NR_sched_getparam:
     case __NR_sched_getscheduler:
+#endif
     case __NR_sched_setscheduler:
       return sandbox::RestrictSchedTarget(GetPolicyPid(), sysno);
     case __NR_prlimit64: