[opengl] Modernize codebase by replacing NULL with nullptr

Fixes -Wzero-as-null-pointer-constant warning.

Test: m
Bug: 68236239
Change-Id: Ia2f91707b277954d5105f6fdb489caad9ef8848c
diff --git a/opengl/libs/EGL/egl_cache.cpp b/opengl/libs/EGL/egl_cache.cpp
index ec548f3..bcf4961 100644
--- a/opengl/libs/EGL/egl_cache.cpp
+++ b/opengl/libs/EGL/egl_cache.cpp
@@ -95,7 +95,7 @@
                     reinterpret_cast<PFNEGLSETBLOBCACHEFUNCSANDROIDPROC>(
                             cnx->egl.eglGetProcAddress(
                                     "eglSetBlobCacheFuncsANDROID"));
-            if (eglSetBlobCacheFuncsANDROID == NULL) {
+            if (eglSetBlobCacheFuncsANDROID == nullptr) {
                 ALOGE("EGL_ANDROID_blob_cache advertised, "
                         "but unable to get eglSetBlobCacheFuncsANDROID");
                 return;
@@ -119,7 +119,7 @@
     if (mBlobCache) {
         mBlobCache->writeToFile();
     }
-    mBlobCache = NULL;
+    mBlobCache = nullptr;
 }
 
 void egl_cache_t::setBlob(const void* key, EGLsizeiANDROID keySize,