Save ~360 bytes.

	add/remove: 1/0 grow/shrink: 0/4 up/down: 104/-463 (-359)
	function                                     old     new   delta
	name_to_int                                    -     104    +104
	proc_pid_lookup                              217     126     -91
	proc_lookupfd_common                         212     121     -91
	proc_task_lookup                             289     194     -95
	__proc_create                                588     402    -186

Link: http://lkml.kernel.org/r/20170912194850.GA17730@avx2Signed-off-by: NAlexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>