e2fsck: don't report uninit extents past EOF invalid

e2fsck: don't report uninit extents past EOF invalid

Commit d3f32c2db8 introduced a regression that caused e2fsck failures
in xfstests generic 013, 070, 083, 091, and 263.  Uninitialized
extents created by fallocate() at the end of file with the
FALLOC_FL_KEEP_SIZE flag were identified as invalid.  However,
because the file size is not increased when FALLOC_FL_KEEP_SIZE is
used, uninitialized extents can correctly contain blocks located past
the end of file.

Fix this by filtering out possible invalid extents if they are
uninitialized and extend past the block containing the end of file.

Signed-off-by: Eric Whitney <enwlinux@gmail.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>