mksquashfs: Fix segfault when SQUASHFS_TRACE is enabled and no -pf flag

Segfault happens when attempting to dump pseudo files in SQUASHFS_TRACE
mode after attempting to dereference NULL pseudo pointer.

Change-Id: I48097cce9b7a7e57fea5411c7d1eb5b5de8dc053
Signed-off-by: Mohamad Ayyash <mkayyash@google.com>
1 file changed