Don't export unnecessary symbol.

Change-Id: I8b1d75a08476c41dd8e3f09fc93a3df617928f88
diff --git a/libc/bionic/malloc_debug_common.cpp b/libc/bionic/malloc_debug_common.cpp
index ccceb14..e33405e 100644
--- a/libc/bionic/malloc_debug_common.cpp
+++ b/libc/bionic/malloc_debug_common.cpp
@@ -293,7 +293,7 @@
 int gMallocDebugLevel;
 
 template<typename FunctionType>
-void InitMallocFunction(void* malloc_impl_handler, FunctionType* func, const char* prefix, const char* suffix) {
+static void InitMallocFunction(void* malloc_impl_handler, FunctionType* func, const char* prefix, const char* suffix) {
     char symbol[128];
     snprintf(symbol, sizeof(symbol), "%s_%s", prefix, suffix);
     *func = reinterpret_cast<FunctionType>(dlsym(malloc_impl_handler, symbol));