jbd2: fix kernel-doc for j_transaction_overhead_buffers

Use the correct struct member name in the kernel-doc notation
to prevent a kernel-doc build warning.

include/linux/jbd2.h:1303: warning: Function parameter or struct member 'j_transaction_overhead_buffers' not described in 'journal_s'
include/linux/jbd2.h:1303: warning: Excess struct member 'j_transaction_overhead' description in 'journal_s'

Fixes: e3a00a23 ("jbd2: precompute number of transaction descriptor blocks")
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Closes: https://lore.kernel.org/linux-next/20240710182252.4c281445@canb.auug.org.au/


Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://patch.msgid.link/20240723051647.3053491-1-rdunlap@infradead.org


Signed-off-by: Theodore Ts'o <tytso@mit.edu>