libext2fs: Fix regression in ext2fs_extent_set_bmap()

Commit 0dc291611 introduced a regression when unmapping the first
block in an extent.  This caused e2fsck -fD to corrupt large
directories if the directory has to shrink by more than one block.
The problem was set_bmap should only go to a next leaf when setting a
first block in an extent, and not when it is unmapping the first block
in an extent.

Addresses-Debian-Bug: #537510

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