Adjust pci_rom_load() to return an indication of whether it allocated
memory or not. Adjust the caller to free it. This fixes a memory leak
when PCI_VGA_RAM_IMAGE_START is not used.
Reported-by: Coverity (CID: 134194)
Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Tom Rini <trini@konsulko.com>