[cmds] Modernize codebase by replacing NULL with nullptr

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

Test: m
Bug: 68236239
Change-Id: I73a0a82e3e32001f8ffb0880250c7023dd8290d3
diff --git a/cmds/lshal/ListCommand.cpp b/cmds/lshal/ListCommand.cpp
index 09eeaa8..8d5f0d2 100644
--- a/cmds/lshal/ListCommand.cpp
+++ b/cmds/lshal/ListCommand.cpp
@@ -1073,9 +1073,9 @@
         i++;
     }
     // getopt_long last option has all zeros
-    ret[i].name = NULL;
+    ret[i].name = nullptr;
     ret[i].has_arg = 0;
-    ret[i].flag = NULL;
+    ret[i].flag = nullptr;
     ret[i].val = 0;
 
     return ret;