media: ngene: avoid unused variable warning

The newly added pdev variable is only used in an #ifdef, causing a
build warning without CONFIG_PCI_MSI, unless we move the declaration
inside the same #ifdef:

drivers/media/pci/ngene/ngene-core.c: In function 'ngene_start':
drivers/media/pci/ngene/ngene-core.c:1328:17: error: unused variable 'pdev' [-Werror=unused-variable]

Fixes: 6795bf62 ("media: ngene: convert kernellog printing from printk() to dev_*() macros")

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Daniel Scheller <d.scheller@gmx.net>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>