unexport access_process_vm

This patch removes the no longer used EXPORT_SYMBOL_GPL(access_process_vm).

Signed-off-by: Adrian Bunk <bunk@kernel.org>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
diff --git a/mm/memory.c b/mm/memory.c
index eefd5b6..9791e47 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -2748,4 +2748,3 @@
 
 	return buf - old_buf;
 }
-EXPORT_SYMBOL_GPL(access_process_vm);