f2fs: support non-4KB block size without packed_ssa feature

f2fs: support non-4KB block size without packed_ssa feature

Currently, F2FS requires the packed_ssa feature to be enabled when
utilizing non-4KB block sizes (e.g., 16KB). This restriction limits
the flexibility of filesystem formatting options.

This patch allows F2FS to support non-4KB block sizes even when the
packed_ssa feature is disabled. It adjusts the SSA calculation logic to
correctly handle summary entries in larger blocks without the packed
layout.

Cc: stable@kernel.org
Fixes: 7ee8bc3942f2 ("f2fs: revert summary entry count from 2048 to 512 in 16kb block support")
Signed-off-by: Daeho Jeong <daehojeong@google.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>