eventfs: Fix bitwise fields for "is_events"

A flag was needed to denote which eventfs_inode was the "events"
directory, so a bit was taken from the "nr_entries" field, as there's not
that many entries, and 2^30 is plenty. But the bit number for nr_entries
was not updated to reflect the bit taken from it, which would add an
unnecessary integer to the structure.

Link: https://lore.kernel.org/linux-trace-kernel/20240102151832.7ca87275@gandalf.local.home



Cc: stable@vger.kernel.org
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Fixes: 7e8358ed ("eventfs: Fix file and directory uid and gid ownership")
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>