scsi: mvumi: use __maybe_unused to hide pm functions

The mvumi scsi hides the references to its suspend/resume functions in
an #ifdef but does not hide the implementation the same way:

drivers/scsi/mvumi.c:2632:12: error: 'mvumi_suspend' defined but not used [-Werror=unused-function]
drivers/scsi/mvumi.c:2651:12: error: 'mvumi_resume' defined but not used [-Werror=unused-function]

This adds __maybe_unused annotations so the compiler knows it can
silently drop them instead of warning, while avoiding the addition of
another #ifdef.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/scsi/mvumi.c

@@ -2629,7 +2629,7 @@ static void mvumi_shutdown(struct pci_dev *pdev)
 	mvumi_flush_cache(mhba);
 }
 
-static int mvumi_suspend(struct pci_dev *pdev, pm_message_t state)
+static int __maybe_unused mvumi_suspend(struct pci_dev *pdev, pm_message_t state)
 {
 	struct mvumi_hba *mhba = NULL;
 
@@ -2648,7 +2648,7 @@ static int mvumi_suspend(struct pci_dev *pdev, pm_message_t state)
 	return 0;
 }
 
-static int mvumi_resume(struct pci_dev *pdev)
+static int __maybe_unused mvumi_resume(struct pci_dev *pdev)
 {
 	int ret;
 	struct mvumi_hba *mhba = NULL;