f2fs: check return value of freeze_super()

freeze_super() can fail, it needs to check its return value and do
error handling in f2fs_resize_fs().

Fixes: 04f0b2ea ("f2fs: ioctl for removing a range from F2FS")
Fixes: b4b10061 ("f2fs: refactor resize_fs to avoid meta updates in progress")
Signed-off-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>