TestLockfileWriteConcurrent: stay below 8192 goroutines
TestLockfileWriteConcurrent: stay below 8192 goroutines

The Go race detector will kill the test if it tries to have more than
8192 goroutines active at once, so start 8,000 instead of 100,000.

Signed-off-by: Nalin Dahyabhai <f562fcb2a0b898bf0be1afc867ea92325d8f825f@redhat.com>

rhatdan/storage,containers/storage,containers/storage,rhatdan/storage,containers/storage,rhatdan/storage