IB/mthca: Use pci_enable_msix_exact() instead of pci_enable_msix()

As result of the deprecation of the MSI-X/MSI enablement functions
pci_enable_msix() and pci_enable_msi_block(), all drivers using these
two interfaces need to be updated to use the new
pci_enable_msi_range() or pci_enable_msi_exact() and
pci_enable_msix_range() or pci_enable_msix_exact() interfaces.

Signed-off-by: Alexander Gordeev <agordeev@redhat.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>
diff --git a/drivers/infiniband/hw/mthca/mthca_main.c b/drivers/infiniband/hw/mthca/mthca_main.c
index 87897b9..ded76c1 100644
--- a/drivers/infiniband/hw/mthca/mthca_main.c
+++ b/drivers/infiniband/hw/mthca/mthca_main.c
@@ -858,13 +858,9 @@
 	entries[1].entry = 1;
 	entries[2].entry = 2;
 
-	err = pci_enable_msix(mdev->pdev, entries, ARRAY_SIZE(entries));
-	if (err) {
-		if (err > 0)
-			mthca_info(mdev, "Only %d MSI-X vectors available, "
-				   "not using MSI-X\n", err);
+	err = pci_enable_msix_exact(mdev->pdev, entries, ARRAY_SIZE(entries));
+	if (err)
 		return err;
-	}
 
 	mdev->eq_table.eq[MTHCA_EQ_COMP ].msi_x_vector = entries[0].vector;
 	mdev->eq_table.eq[MTHCA_EQ_ASYNC].msi_x_vector = entries[1].vector;