x86/asm/32: Remove a bunch of '& 0xffff' from pt_regs segment reads

Now that pt_regs properly defines segment fields as 16-bit on 32-bit
CPUs, there's no need to mask off the high word.

Signed-off-by: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Borislav Petkov <bpetkov@suse.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>

arch/x86/ia32/ia32_signal.c

@@ -226,7 +226,7 @@ static void __user *get_sigframe(struct ksignal *ksig, struct pt_regs *regs,
 	if (ksig->ka.sa.sa_flags & SA_ONSTACK)
 		sp = sigsp(sp, ksig);
 	/* This is the legacy signal stack switching. */
-	else if ((regs->ss & 0xffff) != __USER32_DS &&
+	else if (regs->ss != __USER32_DS &&
 		!(ksig->ka.sa.sa_flags & SA_RESTORER) &&
 		 ksig->ka.sa.sa_restorer)
 		sp = (unsigned long) ksig->ka.sa.sa_restorer;