ocfs2: use memcpy_to_folio() in ocfs2_symlink_get_block()

ocfs2: use memcpy_to_folio() in ocfs2_symlink_get_block()

Replace use of kmap_atomic() with the higher-level construct
memcpy_to_folio().  This removes a use of b_page and supports large folios
as well as being easier to understand.  It also removes the check for
kmap_atomic() failing (because it can't).

Link: https://lkml.kernel.org/r/20250213214533.2242224-1-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Acked-by: Joseph Qi <joseph.qi@linux.alibaba.com>
Cc: Mark Tinguely <mark.tinguely@oracle.com>
Cc: Mark Fasheh <mark@fasheh.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Cc: Changwei Ge <gechangwei@live.cn>
Cc: Jun Piao <piaojun@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>