Verify that all pending requests are justified
Verify that all pending requests are justified

If a request is pending in a lock waiting structure, it has to fulfill
two properties:
- It must be a valid request, not violating any lock order requirements, and
- it must not be possible to fulfill it immediately.
Verify this.

Signed-off-by: Klaus Aehlig <4ce51de36d9068cd7db2eec1151e0f3f95419008@google.com>
Reviewed-by: Petr Pudlak <9d19625f8ee825a2c398462ed335cbcf98f79c32@google.com>

leshchevds/ganeti,apyrgio/ganeti,onponomarev/ganeti,leshchevds/ganeti,bitemyapp/ganeti,grnet/snf-ganeti,bitemyapp/ganeti,onponomarev/ganeti,leshchevds/ganeti,dimara/ganeti,mbakke/ganeti,andir/ganeti,ganeti/ganeti,ganeti/ganeti,andir/ganeti,mbakke/ganeti,yiannist/ganeti,dimara/ganeti,apyrgio/ganeti,mbakke/ganeti,grnet/snf-ganeti,ganeti/ganeti,yiannist/ganeti,ganeti-github-testing/ganeti-test-1,ganeti-github-testing/ganeti-test-1,andir/ganeti,yiannist/ganeti