This reverts commit 
9483f40d8d01918b399b4e24d0c1111db0afffeb.
Some devices stop to connect with above commit, see:
https://bugzilla.kernel.org/show_bug.cgi?id=61621
Since there is no clear benefit of having MSI enabled, just revert
change to fix the problem.
Cc: stable@vger.kernel.org # 3.11+
Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com>
Acked-by: Jakub Kicinski <kubakici@wp.pl>
Acked-by: Gertjan van Wingerde <gwingerde@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
                goto exit_release_regions;
        }
 
-       pci_enable_msi(pci_dev);
-
        hw = ieee80211_alloc_hw(sizeof(struct rt2x00_dev), ops->hw);
        if (!hw) {
                rt2x00_probe_err("Failed to allocate hardware\n");
                retval = -ENOMEM;
-               goto exit_disable_msi;
+               goto exit_release_regions;
        }
 
        pci_set_drvdata(pci_dev, hw);
 exit_free_device:
        ieee80211_free_hw(hw);
 
-exit_disable_msi:
-       pci_disable_msi(pci_dev);
-
 exit_release_regions:
        pci_release_regions(pci_dev);
 
        rt2x00pci_free_reg(rt2x00dev);
        ieee80211_free_hw(hw);
 
-       pci_disable_msi(pci_dev);
-
        /*
         * Free the PCI device data.
         */