We're missing an unlock in case installing the signal handler failed.
Fortunately, we barely see this error in real life.
Fixes: a960d6642d ("util/oslib-posix: Support concurrent os_mem_prealloc() invocation")
Fixes: CID 1468941
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Pankaj Gupta <pankaj.gupta@ionos.com>
Cc: Daniel P. Berrangé <berrange@redhat.com>
Cc: Michal Privoznik <mprivozn@redhat.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
Message-Id: <20220111120830.119912-1-david@redhat.com>
Reviewed-by: Pankaj Gupta <pankaj.gupta@ionos.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>