ahci_platform: Remove unneeded ahci_driver.probe assignment

ahci_platform: Remove unneeded ahci_driver.probe assignment

The driver is using platform_driver_probe() during initialization,
so ahci_driver.probe hook is never used.

But it causes the following (harmless, luckily) section mismatch:

  WARNING: vmlinux.o(.data+0x2fb20): Section mismatch in reference
  from the variable ahci_driver to the function .init.text:ahci_probe()

This patch removes the ahci_driver.probe assignment, thus fixes
the warning.

p.s. Note that there's another patch[1] from Rene Bolldorf that
tried to solve the same issue by __refdata annotation. __refdata
says that this reference is actually OK, but in fact it is not OK,
because dereferencing .probe() will cause problems. So the proper
fix is to remove the assignment.

[1] http://kerneltrap.org/mailarchive/linux-kernel/2010/3/18/4549547

Signed-off-by: Anton Vorontsov <avorontsov@mvista.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>