Fix clang-tidy issues in rootx executables

Cleanup memory, use strlcpy

rootx/src/rootx.cxx

@@ -142,7 +142,7 @@ static void SetRootSys()
             int l2 = strlen(ep) + 10;
             char *env = new char[l2];
             snprintf(env, l2, "ROOTSYS=%s", ep);
-            putenv(env);
+            putenv(env); // NOLINT: allocated memory now used by environment variable
          }
       }
       delete [] ep;
@@ -351,6 +351,8 @@ int main(int argc, char **argv)
       fprintf(stderr, "%s: can't start ROOT notebook -- this option is only available when building with CMake, please check that %s exists\n",
               argv[0], arg0);
 
+      delete [] argvv;
+
       return 1;
    }
 
@@ -468,5 +470,7 @@ int main(int argc, char **argv)
    fprintf(stderr, "%s: can't start ROOT -- check that %s exists!\n",
            argv[0], arg0);
 
+   delete [] argvv;
+
    return 1;
 }

rootx/src/rootxx.cxx

@@ -30,6 +30,7 @@
 
 #include "Rtypes.h"
 #include "snprintf.h"
+#include "strlcpy.h"
 
 #include "rootcoreteam.h"
 
@@ -779,8 +780,9 @@ int DrawCredits(bool draw, bool extended)
 
       struct passwd *pwd = getpwuid(getuid());
       if (pwd) {
-         char *name = new char [strlen(pwd->pw_gecos)+1];
-         strcpy(name, pwd->pw_gecos);
+         size_t sz = strlen(pwd->pw_gecos)+1;
+         char *name = new char [sz];
+         strlcpy(name, pwd->pw_gecos, sz);
          char *s = strchr(name, ',');
          if (s) *s = 0;
          char line[1024];