Update to v5.11 kernel headers.

Kernel headers coming from:

Git: https://android.googlesource.com/kernel/common/
Branch: android-mainline
Tag: android-mainline-5.11

Test: Built cuttlefish and flame images. Ran bionic unit tests on both.
Change-Id: Ie60337aafad4bda55af99b6c8fe9f56bf2fa787f
diff --git a/libc/kernel/uapi/linux/snmp.h b/libc/kernel/uapi/linux/snmp.h
index 8d63a3c..40e8fa5 100644
--- a/libc/kernel/uapi/linux/snmp.h
+++ b/libc/kernel/uapi/linux/snmp.h
@@ -129,6 +129,7 @@
   UDP_MIB_SNDBUFERRORS,
   UDP_MIB_CSUMERRORS,
   UDP_MIB_IGNOREDMULTI,
+  UDP_MIB_MEMERRORS,
   __UDP_MIB_MAX
 };
 enum {