paravirt: unstatic leave_mm

Make globally leave_mm visible, specifically so that Xen can use it to
shoot-down lazy uses of cr3.

Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Signed-off-by: Chris Wright <chrisw@sous-sol.org>
diff --git a/include/asm-i386/mmu_context.h b/include/asm-i386/mmu_context.h
index 8198d1c..7eb0b0b 100644
--- a/include/asm-i386/mmu_context.h
+++ b/include/asm-i386/mmu_context.h
@@ -32,6 +32,8 @@
 #endif
 }
 
+void leave_mm(unsigned long cpu);
+
 static inline void switch_mm(struct mm_struct *prev,
 			     struct mm_struct *next,
 			     struct task_struct *tsk)