f2fs: fix to enable compress for newly created file if extension matches

If compress_extension is set, and a newly created file matches the
extension, the file could be marked as compression file. However,
if inline_data is also enabled, there is no chance to check its
extension since f2fs_should_compress() always returns false.

This patch moves set_compress_inode(), which do extension check, in
f2fs_should_compress() to check extensions before setting inline
data flag.

Fixes: 7165841d578e ("f2fs: fix to check inline_data during compressed inode conversion")
Signed-off-by: Sheng Yong <shengyong@oppo.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>