Commit 465665f78a7 ("mips: Kill pointless destroy_irq()") removed
the destroy_irq(). So remove the leftover one in xlp_setup_msix()
to fix build error.
arch/mips/pci/msi-xlp.c: In function 'xlp_setup_msix':
arch/mips/pci/msi-xlp.c:447:3: error: implicit declaration of function 'destroy_irq'..
cc1: some warnings being treated as errors
make[1]: *** [arch/mips/pci/msi-xlp.o] Error 1
make: *** [arch/mips/pci/] Error 2