4.0-stable review patch.  If anyone has any objections, please let me know.

------------------

From: James Hogan <redacted>

commit 5f35b9cd553fd64415b563497d05a563c988dbd6 upstream.

Commit 334c86c494b9 ("MIPS: IRQ: Add stackoverflow detection") added
kernel stack overflow detection, however it only enabled it conditional
upon the preprocessor definition DEBUG_STACKOVERFLOW, which is never
actually defined. The Kconfig option is called DEBUG_STACKOVERFLOW,
which manifests to the preprocessor as CONFIG_DEBUG_STACKOVERFLOW, so
switch it to using that definition instead.

Fixes: 334c86c494b9 ("MIPS: IRQ: Add stackoverflow detection")
Signed-off-by: James Hogan <redacted>
Cc: Ralf Baechle <redacted>
Cc: Adam Jiang <redacted>
Cc: linux-mips@linux-mips.org
Patchwork: http://patchwork.linux-mips.org/patch/10531/
Signed-off-by: Ralf Baechle <redacted>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 arch/mips/kernel/irq.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/arch/mips/kernel/irq.c
+++ b/arch/mips/kernel/irq.c

@@ -109,7 +109,7 @@ void __init init_IRQ(void)
 #endif
 }
 
-#ifdef DEBUG_STACKOVERFLOW
+#ifdef CONFIG_DEBUG_STACKOVERFLOW
 static inline void check_stack_overflow(void)
 {
 	unsigned long sp;