lib: delete lib/find_last_bit.c

The file lib/find_last_bit.c was no longer used and supposed to be
deleted by commit 8f6f19dd ("lib: move find_last_bit to
lib/find_next_bit.c") but that delete didn't happen.  This gets rid of
it.
Signed-off-by: Yury Norov <yury.norov@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

lib/find_last_bit.c

-/* find_last_bit.c: fallback find next bit implementation
- *
- * Copyright (C) 2008 IBM Corporation
- * Written by Rusty Russell <rusty@rustcorp.com.au>
- * (Inspired by David Howell's find_next_bit implementation)
- *
- * Rewritten by Yury Norov <yury.norov@gmail.com> to decrease
- * size and improve performance, 2015.
- *
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public License
- * as published by the Free Software Foundation; either version
- * 2 of the License, or (at your option) any later version.
- */
-
-#include <linux/bitops.h>
-#include <linux/bitmap.h>
-#include <linux/export.h>
-#include <linux/kernel.h>
-
-#ifndef find_last_bit
-
-unsigned long find_last_bit(const unsigned long *addr, unsigned long size)
-{
-	if (size) {
-		unsigned long val = BITMAP_LAST_WORD_MASK(size);
-		unsigned long idx = (size-1) / BITS_PER_LONG;
-
-		do {
-			val &= addr[idx];
-			if (val)
-				return idx * BITS_PER_LONG + __fls(val);
-
-			val = ~0ul;
-		} while (idx--);
-	}
-	return size;
-}
-EXPORT_SYMBOL(find_last_bit);
-
-#endif