a-dump-oops: Add new WARNING pattern

Kernel commit dcb6b45254e2281b6f99ea7f2d51343954aa3ba8 [1] breaks
parsing of koops warnings. Add new pattern to the list of suspicious
strings.

Closes #723.

[1] https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/kernel/panic.c?id=dcb6b45254e2281b6f99ea7f2d51343954aa3ba8

Signed-off-by: Martin Milata <mmilata@redhat.com>
Merge pull request #724 from abrt/gh723-dump-oops-warn

a-dump-oops: Add new WARNING pattern

Kernel commit dcb6b45254e2281b6f99ea7f2d51343954aa3ba8 [1] breaks
parsing of koops warnings. Add new pattern to the list of suspicious
strings.

Closes #723.

[1] https://git.kernel.org/cgit/linux/kernel/git/torvalds/