Fix clang compilation issues:

Fix test files for RULE-1-3 and CON38-C

Author: mbaluda

c/common/test/rules/preservesafetywhenusingconditionvariables/test.c

@@ -29,7 +29,6 @@ void f1() {
   }
 
   mtx_destroy(&mxl);
-  return 0;
 }
 
 void f2() {
@@ -48,5 +47,4 @@ void f2() {
   }
 
   mtx_destroy(&mxl);
-  return 0;
 }

c/misra/test/rules/RULE-1-3/test.c.clang

@@ -0,0 +1,25 @@
+// void main(void) { // COMPLIANT does not compile in clang
+// }
+
+int ____codeql_coding_standards_m1(int argc, char **argv) { // NON_COMPLIANT
+  return 0;
+}
+
+void ____codeql_coding_standards_m2(char *argc, char **argv) { // NON_COMPLIANT
+}
+
+int ____codeql_coding_standards_m3(int argc, char *argv) { // NON_COMPLIANT
+  return 0;
+}
+
+int ____codeql_coding_standards_m4() { // NON_COMPLIANT
+  return 0;
+}
+
+int ____codeql_coding_standards_m5(int argc, int *argv) { // NON_COMPLIANT
+  return 0;
+}
+
+int ____codeql_coding_standards_m6(int argc, int **argv) { // NON_COMPLIANT
+  return 0;
+}