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: I2b6600d7a1db9071878380c59e8b4d79a10c766a
Bug: 361829529
(cherry picked from commit 7d009e04)
Signed-off-by: Daeho Jeong <daehojeong@google.com>