PCI: rpaphp: Remove global num_slots variable

Cleanup cruft: remove the global "num_slots" variable; 
although scattered across multiple files, it is used only 
once, in a debug statement.

Signed-off-by: Linas Vepstas <linas@austin.ibm.com>
Cc: John Rose <johnrose@austin.ibm.com>
Signed-off-by: Kristen Carlson Accardi <kristen.c.accardi@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>