qlcnic: Enhance logic to calculate msix vectors.

o Refactored MSI-x vector calculation for All adapters.
  Decoupled logic in the code which was using same call to
  request MSI-x vectors in default driver load, as well as
  during set_channel() operation for TSS/RSS. This refactoring
  simplifies code for TSS/RSS code path as well as probe path
  of the driver load for all adapters.

Signed-off-by: Himanshu Madhani <himanshu.madhani@qlogic.com>
Signed-off-by: David S. Miller <davem@davemloft.net>