fs/proc/base.c: save decrement during lookup/readdir in /proc/$PID

Comparison for "<" works equally well as comparison for "<=" but one
SUB/LEA is saved (no, it is not optimised away, at least here).

Link: http://lkml.kernel.org/r/20161122195143.GA29812@avx2
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

fs/proc/base.c

@@ -2412,14 +2412,14 @@ static struct dentry *proc_pident_lookup(struct inode *dir,
 	 * Yes, it does not scale. And it should not. Don't add
 	 * new entries into /proc/<tgid>/ without very good reasons.
 	 */
-	last = &ents[nents - 1];
-	for (p = ents; p <= last; p++) {
+	last = &ents[nents];
+	for (p = ents; p < last; p++) {
 		if (p->len != dentry->d_name.len)
 			continue;
 		if (!memcmp(dentry->d_name.name, p->name, p->len))
 			break;
 	}
-	if (p > last)
+	if (p >= last)
 		goto out;
 
 	error = proc_pident_instantiate(dir, dentry, task, p);
@@ -2444,7 +2444,7 @@ static int proc_pident_readdir(struct file *file, struct dir_context *ctx,
 	if (ctx->pos >= nents + 2)
 		goto out;
 
-	for (p = ents + (ctx->pos - 2); p <= ents + nents - 1; p++) {
+	for (p = ents + (ctx->pos - 2); p < ents + nents; p++) {
 		if (!proc_fill_cache(file, ctx, p->name, p->len,
 				proc_pident_instantiate, task, p))
 			break;