media: cx23885: add ioremap return check and cleanup

In the Linux kernel, the following vulnerability has been resolved: media: cx23885: add ioremap return check and cleanup Add a check for the return value of pci_ioremap_bar() in cx23885_dev_setup(). If ioremap for BAR0 fails, release the already allocated PCI memory region, decrement the device count, and return -ENODEV. This prevents a potential null pointer dereference and ensures proper cleanup on memory mapping failure.