Fix edge case when i_size doesn't get fixed until second e2fsck run

Fix edge case when i_size doesn't get fixed until second e2fsck run

Don't assume that a special device is bogus just because i_blocks is
non-zero.  The i_blocks field could get adjusted later, and if this
happens it will confuse the e2fsck_process_bad_inode() in pass 2.  In
practice true garbage inodes will have random non-zero in
i_blocks[4..15], so there's no point doing the check for an illegal
i_blocks value.

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>