Update to v5.0 kernel headers.

Test: Builds and boots on taimen.
Change-Id: I13843bf1ab30ea89a50852adc88f2cba8401bded
diff --git a/libc/kernel/uapi/linux/sysctl.h b/libc/kernel/uapi/linux/sysctl.h
index 24d8362..ae0f44a 100644
--- a/libc/kernel/uapi/linux/sysctl.h
+++ b/libc/kernel/uapi/linux/sysctl.h
@@ -124,6 +124,7 @@
   KERN_NMI_WATCHDOG = 75,
   KERN_PANIC_ON_NMI = 76,
   KERN_PANIC_ON_WARN = 77,
+  KERN_PANIC_PRINT = 78,
 };
 enum {
   VM_UNUSED1 = 1,