EDAC/igen6: Fix error handling in igen6_edac driver

The igen6_edac driver calls device_initialize() for all memory
controllers in igen6_register_mci(), but misses corresponding
put_device() calls in error paths and during normal shutdown in
igen6_unregister_mcis().

Adding the missing put_device() calls improves code readability and
ensures proper reference counting for the device structure.

Found by code review.

Signed-off-by: Ma Ke <make24@iscas.ac.cn>
Reviewed-by: Qiuxu Zhuo <qiuxu.zhuo@intel.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Link: https://patch.msgid.link/20251105090244.23327-1-make24@iscas.ac.cn

Author: Ma Ke

drivers/edac/igen6_edac.c

@@ -1300,6 +1300,7 @@ static int igen6_register_mci(int mc, void __iomem *window, struct pci_dev *pdev
 	imc->mci = mci;
 	return 0;
 fail3:
+	put_device(&imc->dev);
 	mci->pvt_info = NULL;
 	kfree(mci->ctl_name);
 fail2:
@@ -1326,6 +1327,7 @@ static void igen6_unregister_mcis(void)
 		kfree(mci->ctl_name);
 		mci->pvt_info = NULL;
 		edac_mc_free(mci);
+		put_device(&imc->dev);
 		iounmap(imc->window);
 	}
 }