mstress: Fix install collision.

There were two testcases installing a binary named 'dummy' which
resulted into a collision at the install phase. (In the end mstress may
ended up working with the wrong binary)

Reported-by: Haresh Chavda <HACAD@vestas.com>
Signed-off-by: Cyril Hrubis <chrubis@suse.cz>
cap_bound: remove check_for_libcap.sh and dummy.c

These two files were intended as poor man's configure script and are not
needed anymore.

Signed-off-by: Cyril Hrubis <chrubis@suse.cz>