xen/p2m: Fix module linking error.

Fixes:
ERROR: "m2p_find_override_pfn" [drivers/block/xen-blkfront.ko] undefined!

Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>

1 files changed, 1 insertions, 0 deletions

diff --git a/arch/x86/xen/p2m.c b/arch/x86/xen/p2m.c
index 40d51225ff08..8f2251d2a3f8 100644
--- a/arch/x86/xen/p2m.c
+++ b/arch/x86/xen/p2m.c
@@ -507,3 +507,4 @@ unsigned long m2p_find_override_pfn(unsigned long mfn, unsigned long pfn)
 
         return ret;
 }
+EXPORT_SYMBOL_GPL(m2p_find_override_pfn);