x86/PCI: Abort if legacy init fails

If the legacy PCI init fails, then there are no PCI config space accesors
available, but the code continues and tries to scan the busses, which fails
due to the lack of config space accessors.

Return right away, if the last init fallback fails.

Switch the few printks to pr_info while at it.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Bjorn Helgaas <helgaas@kernel.org>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: linux-pci@vger.kernel.org
Link: http://lkml.kernel.org/r/20170316215057.047576516@linutronix.de


Signed-off-by: Thomas Gleixner <tglx@linutronix.de>