tracing/user_events: Charge event allocs to cgroups

Operators need a way to limit how much memory cgroups use. User events need
to be included into that accounting. Fix this by using GFP_KERNEL_ACCOUNT
for allocations generated by user programs for user_event tracing.

Link: https://lkml.kernel.org/r/20230328235219.203-11-beaub@linux.microsoft.com



Signed-off-by: Beau Belgrave <beaub@linux.microsoft.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>