coccinelle: pool_zalloc-simple: drop the pci_pool_alloc rules

pci_pool_alloc() and pci_pool_zalloc() were removed by commit
88dee3b0efe4 ("PCI: Remove unused pci_pool wrappers").

So drop the pci_pool_alloc rules.

No functional change.

Signed-off-by: Sang-Heon Jeon <ekffu200098@gmail.com>
Signed-off-by: Julia Lawall <Julia.Lawall@inria.fr>