BACKPORT: f2fs: fix to handle segment allocation failure correctly

If CONFIG_F2FS_CHECK_FS is off, and for very rare corner case that
we run out of free segment, we should not panic kernel, instead,
let's handle such error correctly in its caller.

Signed-off-by: Chao Yu <chao@kernel.org>
Tested-by: Zhiguo Niu <zhiguo.niu@unisoc.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

Change-Id: I4e7d90895d82687ae6ec6b64b2de222f1ee2ee9e
Bug: 361829529
(cherry picked from commit 7d009e04)
Signed-off-by: Daeho Jeong <daehojeong@google.com>