freezer.h uses task_struct fields so it should include sched.h.

  CC [M]  fs/jfs/jfs_txnmgr.o
In file included from fs/jfs/jfs_txnmgr.c:49:
include/linux/freezer.h: In function 'frozen':
include/linux/freezer.h:9: error: dereferencing pointer to incomplete type
include/linux/freezer.h:9: error: 'PF_FROZEN' undeclared (first use in this function)
include/linux/freezer.h:9: error: (Each undeclared identifier is reported only once
include/linux/freezer.h:9: error: for each function it appears in.)
include/linux/freezer.h: In function 'freezing':
include/linux/freezer.h:17: error: dereferencing pointer to incomplete type
include/linux/freezer.h:17: error: 'PF_FREEZE' undeclared (first use in this function)
include/linux/freezer.h: In function 'freeze':
include/linux/freezer.h:26: error: dereferencing pointer to incomplete type
include/linux/freezer.h:26: error: 'PF_FREEZE' undeclared (first use in this function)
include/linux/freezer.h: In function 'do_not_freeze':
include/linux/freezer.h:34: error: dereferencing pointer to incomplete type
include/linux/freezer.h:34: error: 'PF_FREEZE' undeclared (first use in this function)
include/linux/freezer.h: In function 'thaw_process':
include/linux/freezer.h:43: error: dereferencing pointer to incomplete type
include/linux/freezer.h:43: error: 'PF_FROZEN' undeclared (first use in this function)
include/linux/freezer.h:44: warning: implicit declaration of function 'wake_up_process'
include/linux/freezer.h: In function 'frozen_process':
include/linux/freezer.h:55: error: dereferencing pointer to incomplete type
include/linux/freezer.h:55: error: dereferencing pointer to incomplete type
include/linux/freezer.h:55: error: 'PF_FREEZE' undeclared (first use in this function)
include/linux/freezer.h:55: error: 'PF_FROZEN' undeclared (first use in this function)
fs/jfs/jfs_txnmgr.c: In function 'freezing':
include/linux/freezer.h:18: warning: control reaches end of non-void function
make[2]: *** [fs/jfs/jfs_txnmgr.o] Error 1

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Acked-by: Dave Kleikamp <shaggy@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>