x86: fix broken TASK_SIZE for ia32_aout

Setting TIF_IA32 in load_aout_binary() used to be enough; these days
TASK_SIZE is controlled by TIF_ADDR32 and that one doesn't get set
there.  Switch to use of set_personality_ia32()...
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

arch/x86/ia32/ia32_aout.c

@@ -294,8 +294,7 @@ static int load_aout_binary(struct linux_binprm *bprm, struct pt_regs *regs)
 
 	/* OK, This is the point of no return */
 	set_personality(PER_LINUX);
-	set_thread_flag(TIF_IA32);
-	current->mm->context.ia32_compat = 1;
+	set_personality_ia32(false);
 
 	setup_new_exec(bprm);