powerpc: Fix typo in runlatch code

Commit fe1952fc0afb9a2e4c79f103c08aef5d13db1873
"powerpc: Rework runlatch code" has a nasty typo
where it uses "TLF_RUNLATCH" instead of "_TLF_RUNLATCH"
(bit number instead of bit mask), causing some flags to
be potentially lost such as _TLF_RESTORE_SIGMASK

(Brown paper bag for me ! We should be able to make
that break at compile time with a bit of magic, any
volunteer ?)

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

arch/powerpc/kernel/process.c

@@ -1235,7 +1235,7 @@ void __ppc64_runlatch_on(void)
 	ctrl |= CTRL_RUNLATCH;
 	mtspr(SPRN_CTRLT, ctrl);
 
-	ti->local_flags |= TLF_RUNLATCH;
+	ti->local_flags |= _TLF_RUNLATCH;
 }
 
 /* Called with hard IRQs off */
@@ -1244,7 +1244,7 @@ void __ppc64_runlatch_off(void)
 	struct thread_info *ti = current_thread_info();
 	unsigned long ctrl;
 
-	ti->local_flags &= ~TLF_RUNLATCH;
+	ti->local_flags &= ~_TLF_RUNLATCH;
 
 	ctrl = mfspr(SPRN_CTRLF);
 	ctrl &= ~CTRL_RUNLATCH;