make get_file() return its argument

arch/ia64/kernel/perfmon.c

drivers/base/dma-buf.c

drivers/staging/omapdrm/omap_gem.c

drivers/tty/tty_io.c

fs/autofs4/waitq.c

fs/fuse/dev.c

fs/nfsd/nfs4state.c

fs/proc/base.c

fs/select.c

include/linux/fs.h

mm/fremap.c

mm/mmap.c

mm/nommu.c

net/compat.c

net/core/scm.c

security/selinux/hooks.c