spec: fix build error
spec: fix build error

Since the header files won't be installed, so we need to remove it
from the spec file too.

Signed-off-by: Xiubo Li <d6cd9ec469dfb11098caa077ea0b7b3220fc70dc@redhat.com>

agrover/tcmu-runner,open-iscsi/tcmu-runner,open-iscsi/tcmu-runner