After commit 26b5a079197c ("f2fs: cleanup dirty pages if recover failed"),
f2fs_sync_inode_meta() is only used in checkpoint.c, so
f2fs_sync_inode_meta() should only be visible inside. Delete the
declaration in the header file and change f2fs_sync_inode_meta()
to static.
Signed-off-by: Li Zetao <lizetao1@xxxxxxxxxx>