tracing: Fix disabling of soft disable

The comment on the soft disable 'disable' case of
__ftrace_event_enable_disable() states that the soft disable bit
should be cleared in that case, but currently only the soft mode bit
is actually cleared.

This essentially leaves the standard non-soft-enable enable/disable
paths as the only way to clear the soft disable flag, but the soft
disable bit should also be cleared when removing a trigger with '!'.

Also, the SOFT_DISABLED bit should never be set if SOFT_MODE is
cleared.

This fixes the above discrepancies.

Link: http://lkml.kernel.org/r/b9c68dd50bc07019e6c67d3f9b29be4ef1b2badb.1372479499.git.tom.zanussi@linux.intel.com

Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

kernel/trace/trace_events.c

@@ -291,9 +291,11 @@ static int __ftrace_event_enable_disable(struct ftrace_event_file *file,
 			}
 			call->class->reg(call, TRACE_REG_UNREGISTER, file);
 		}
-		/* If in SOFT_MODE, just set the SOFT_DISABLE_BIT */
+		/* If in SOFT_MODE, just set the SOFT_DISABLE_BIT, else clear it */
 		if (file->flags & FTRACE_EVENT_FL_SOFT_MODE)
 			set_bit(FTRACE_EVENT_FL_SOFT_DISABLED_BIT, &file->flags);
+		else
+			clear_bit(FTRACE_EVENT_FL_SOFT_DISABLED_BIT, &file->flags);
 		break;
 	case 1:
 		/*