Fix #1869 Compiler Compatability for clang for CERT-C++ rule DCL51-CPP

tzname is char*[2] in the standard libraries of both clang and gcc. This will
allow the test code to compile, and still triggers a non-compliance query
result.

Author: MichaelRFairhurst

cpp/cert/test/rules/DCL51-CPP/ObjectReusesReservedName.expected

@@ -1 +1 @@
-| test.cpp:18:5:18:10 | tzname | The variable $@ reuses a reserved standard library name. | test.cpp:18:5:18:10 | tzname | tzname |
+| test.cpp:18:7:18:12 | tzname | The variable $@ reuses a reserved standard library name. | test.cpp:18:7:18:12 | tzname | tzname |

cpp/cert/test/rules/DCL51-CPP/test.cpp

@@ -15,7 +15,7 @@ enum {
 
 // int NULL = 0; // NON_COMPLIANT, but not supported by compilers in practice
 
-int tzname = 0; // NON_COMPLIANT
+char* tzname[2]; // NON_COMPLIANT
 
 void min() {} // NON_COMPLIANT