fix(PISharedMemory): reset data and unlink on mmap failure

When mmap() returned MAP_FAILED, data stayed as (void*)-1, causing
subsequent read/write/close to pass the null guard and crash.
Now resets data=nullptr, and calls shm_unlink when owner=true to
avoid orphaned shared memory objects.

libs/main/io_devices/pisharedmemory.cpp

@@ -144,6 +144,9 @@ bool PISharedMemory::openDevice() {
 	::close(fd);
 	if (PRIVATE->data == MAP_FAILED) {
 		piCoutObj << "mmap error," << errorString();
+		if (PRIVATE->owner) shm_unlink((const char *)PRIVATE->name.data());
+		PRIVATE->data  = nullptr;
+		PRIVATE->owner = false;
 		return false;
 	}
 	// piCoutObj << "opened" << PRIVATE->data;