ACPI: simplify buffer management for acpi_pci_bind() etc.

use ACPI_ALLOCATE_BUFFER to remove the allocations
within acpi_pci_bind(), acpi_pci_unbind() and acpi_pci_bind_root().
While there, delete some unnecessary param inits from those routines.

Delete concept of ACPI_PATHNAME_MAX, since this was the last use.

Signed-off-by: Len Brown <len.brown@intel.com>

include/acpi/platform/aclinux.h

@@ -70,9 +70,6 @@
 #define ACPI_EXPORT_SYMBOL(symbol)  EXPORT_SYMBOL(symbol);
 #define strtoul                     simple_strtoul
 
-/* Full namespace pathname length limit - arbitrary */
-#define ACPI_PATHNAME_MAX              256
-
 #else				/* !__KERNEL__ */
 
 #include <stdarg.h>