Modernize codebase by replacing NULL with nullptr

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

Test: m
Bug: 68236239
Change-Id: I226a0599db4f7c3557e55cade7869d00bd314949
diff --git a/netutils_wrappers/NetUtilsWrapper-1.0.cpp b/netutils_wrappers/NetUtilsWrapper-1.0.cpp
index fc1d9a8..94c08ff 100644
--- a/netutils_wrappers/NetUtilsWrapper-1.0.cpp
+++ b/netutils_wrappers/NetUtilsWrapper-1.0.cpp
@@ -45,7 +45,7 @@
     "ndc",
     "tc",
     "ip",
-    NULL,
+    nullptr,
 };
 
 // List of regular expressions of expected commands.
@@ -105,7 +105,7 @@
 // This is the only gateway for vendor programs to reach net utils.
 int doMain(int argc, char **argv) {
     char *progname = argv[0];
-    char *basename = NULL;
+    char *basename = nullptr;
 
     basename = strrchr(progname, '/');
     basename = basename ? basename + 1 : progname;