x86: x86-32 thread_struct.debugreg

This replaces the debugreg[7] member of thread_struct with individual
members debugreg0, etc.  This saves two words for the dummies 4 and 5,
and harmonizes the code between 32 and 64.

Signed-off-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
diff --git a/arch/x86/kernel/traps_32.c b/arch/x86/kernel/traps_32.c
index 931ef10..2771355 100644
--- a/arch/x86/kernel/traps_32.c
+++ b/arch/x86/kernel/traps_32.c
@@ -852,7 +852,7 @@
 
 	/* Mask out spurious debug traps due to lazy DR7 setting */
 	if (condition & (DR_TRAP0|DR_TRAP1|DR_TRAP2|DR_TRAP3)) {
-		if (!tsk->thread.debugreg[7])
+		if (!tsk->thread.debugreg7)
 			goto clear_dr7;
 	}
 
@@ -860,7 +860,7 @@
 		goto debug_vm86;
 
 	/* Save debug status register where ptrace can see it */
-	tsk->thread.debugreg[6] = condition;
+	tsk->thread.debugreg6 = condition;
 
 	/*
 	 * Single-stepping through TF: make sure we ignore any events in