libsupport: fix (very potential) NULL dereference

It's a very rare set of circumstances (requiring deleting profile
sections, which e2fsprogs doesn't do) that might trigger a NULL
derference, but fix it for robustness's sake, maybe some day someone
will use that functionality.

Fixes-Coverity-Bug: 207508
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
1 file changed