stacktrace.h: remove duplicate declaration task_struct
stacktrace.h: remove duplicate declaration task_struct

There is duplicate declaration for struct task_struct.
One can be removed safely.

Signed-off-by: Himanshu Maithani <79454fc903d76519047968fda4f82d2006cae5ad@gmail.com>
Signed-off-by: Jiri Kosina <ed58f755cc8caaf10c3e8c731a8b86fb8f13d6cb@suse.cz>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs