ppc64 segment table rework. We preload segments for both segment

table and SLB based machines. We support both preloading all
16 segments in 32b or just the PC and SP segments (32b and 64b).

arch/ppc64/kernel/signal32.c

@@ -239,7 +239,6 @@ long sys32_sigreturn(unsigned long r3, unsigned long r4, unsigned long r5,
 	int ret;
 	elf_gregset_t32 saved_regs;  /* an array of ELF_NGREG unsigned ints (32 bits) */
 	sigset_t set;
-	unsigned int prevsp;
 
 	sc = (struct sigcontext32_struct *)(regs->gpr[1] + __SIGNAL_FRAMESIZE32);
 	if (copy_from_user(&sigctx, sc, sizeof(sigctx)))
@@ -1150,7 +1149,7 @@ handle_signal32(unsigned long sig, struct k_sigaction *ka,
 			goto badframe; 
 		}
 	} else {
-		/* Put another sigcontext on the stack */
+		/* Put a sigcontext on the stack */
 		*newspp -= sizeof(*sc);
 		sc = (struct sigcontext32_struct *)(u64)*newspp;
 		if (verify_area(VERIFY_WRITE, sc, sizeof(*sc)))