platform/x86: mlx-platform: call pci_dev_put() to balance the refcount

mlxplat_pci_fpga_device_init() calls pci_get_device() but does not
release the refcount on error path. Call pci_dev_put() on the error path
and in mlxplat_pci_fpga_device_exit() to fix this.

This bug was found by an experimental static analysis tool that I am
developing.

Fixes: 02daa22 ("platform: mellanox: Add initial support for PCIe based programming logic device")
Signed-off-by: Joe Hattori <joe@pf.is.s.u-tokyo.ac.jp>
Reviewed-by: Vadim Pasternak <vadimp@nvidia.com>
Link: https://lore.kernel.org/r/20241216022538.381209-1-joe@pf.is.s.u-tokyo.ac.jp
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>

Author: joehattori

drivers/platform/x86/mlx-platform.c

@@ -6237,6 +6237,7 @@ mlxplat_pci_fpga_device_init(unsigned int device, const char *res_name, struct p
 fail_pci_request_regions:
 	pci_disable_device(pci_dev);
 fail_pci_enable_device:
+	pci_dev_put(pci_dev);
 	return err;
 }
 
@@ -6247,6 +6248,7 @@ mlxplat_pci_fpga_device_exit(struct pci_dev *pci_bridge,
 	iounmap(pci_bridge_addr);
 	pci_release_regions(pci_bridge);
 	pci_disable_device(pci_bridge);
+	pci_dev_put(pci_bridge);
 }
 
 static int