Stop using weak symbols in libvndksupport.

These weak symbols are no longer necessary because we no longer
need to statically link libvndksupport.

Furthermore, these symbols are not really optional when libvndksupport is
dynamically linked. When the library is linked with --as-needed the linker
may drop the reference to libdl_android.so, which leads to a failure to boot.

Bug: 146456667
Change-Id: I4d2290d8d0206e0d89665d4d872a7c53b3e1531b
diff --git a/libvndksupport/linker.cpp b/libvndksupport/linker.cpp
index cf0f618..30b9c2e 100644
--- a/libvndksupport/linker.cpp
+++ b/libvndksupport/linker.cpp
@@ -26,9 +26,7 @@
 
 #include <initializer_list>
 
-__attribute__((weak)) extern "C" android_namespace_t* android_get_exported_namespace(const char*);
-__attribute__((weak)) extern "C" void* android_dlopen_ext(const char*, int,
-                                                          const android_dlextinfo*);
+extern "C" android_namespace_t* android_get_exported_namespace(const char*);
 
 namespace {
 
@@ -42,10 +40,8 @@
 static VendorNamespace get_vendor_namespace() {
     static VendorNamespace result = ([] {
         for (const char* name : {"sphal", "default"}) {
-            if (android_get_exported_namespace != nullptr) {
-                if (android_namespace_t* ns = android_get_exported_namespace(name)) {
-                    return VendorNamespace{ns, name};
-                }
+            if (android_namespace_t* ns = android_get_exported_namespace(name)) {
+                return VendorNamespace{ns, name};
             }
         }
         return VendorNamespace{};
@@ -59,10 +55,6 @@
     if (getpid() == 1) {
         return 0;
     }
-    if (android_get_exported_namespace == nullptr) {
-        ALOGD("android_get_exported_namespace() not available. Assuming system process.");
-        return 0;
-    }
 
     // In vendor process, 'vndk' namespace is not visible, whereas in system
     // process, it is.
@@ -76,10 +68,7 @@
                 .flags = ANDROID_DLEXT_USE_NAMESPACE,
                 .library_namespace = vendor_namespace.ptr,
         };
-        void* handle = nullptr;
-        if (android_dlopen_ext != nullptr) {
-            handle = android_dlopen_ext(name, flag, &dlextinfo);
-        }
+        void* handle = android_dlopen_ext(name, flag, &dlextinfo);
         if (!handle) {
             ALOGE("Could not load %s from %s namespace: %s.", name, vendor_namespace.name,
                   dlerror());