[PATCH] rename struct pspace to struct pid_namespace

Rename struct pspace to struct pid_namespace for consistency with other
namespaces (uts_namespace and ipc_namespace).  Also rename
include/linux/pspace.h to include/linux/pid_namespace.h and variables from
pspace to pid_ns.

Signed-off-by: Sukadev Bhattiprolu <sukadev@us.ibm.com>
Signed-off-by: Cedric Le Goater <clg@fr.ibm.com>
Cc: Kirill Korotaev <dev@openvz.org>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Herbert Poetzl <herbert@13thfloor.at>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>