ARM: Fix the world famous typo with is_gate_vma()

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
diff --git a/arch/arm/kernel/process.c b/arch/arm/kernel/process.c
index d03b5bd..e28d43f 100644
--- a/arch/arm/kernel/process.c
+++ b/arch/arm/kernel/process.c
@@ -459,7 +459,7 @@
 {
 	return in_gate_area(NULL, addr);
 }
-#define is_gate_vma(vma)	((vma) = &gate_vma)
+#define is_gate_vma(vma)	((vma) == &gate_vma)
 #else
 #define is_gate_vma(vma)	0
 #endif