[binutils-gdb] Add a check for a NULL table pointer before attempting to compute a DWARF filename.

[sergiodj+buildbot@sergiodj.net]

*** TEST RESULTS FOR COMMIT 6327533b1fd29fa86f6bf34e61c332c010e3c689 ***

Author: Nick Clifton <nickc@redhat.com>
Branch: master
Commit: 6327533b1fd29fa86f6bf34e61c332c010e3c689

Add a check for a NULL table pointer before attempting to compute a DWARF filename.

	PR 23065
	* dwarf2.c (concat_filename): Check for a NULL table pointer.