RULE-21-21: Simplify alert message

Author: lcartey

c/misra/src/rules/RULE-21-21/SystemOfStdlibhUsed.ql

@@ -19,4 +19,4 @@ where
   not isExcluded(call, BannedPackage::systemOfStdlibhUsedQuery()) and
   call.getTarget() = target and
   target.hasGlobalOrStdName("system")
-select call, "Call to banned function $@.", target, target.getName()
+select call, "Call to banned function " + target.getName() + "."

c/misra/test/rules/RULE-21-21/SystemOfStdlibhUsed.expected

@@ -1,5 +1,5 @@
-| test.c:10:3:10:8 | call to system | Call to banned function $@. | test.c:4:5:4:10 | system | system |
-| test.c:18:3:18:8 | call to system | Call to banned function $@. | test.c:4:5:4:10 | system | system |
-| test.c:19:3:19:8 | call to system | Call to banned function $@. | test.c:4:5:4:10 | system | system |
-| test.c:20:3:20:8 | call to system | Call to banned function $@. | test.c:4:5:4:10 | system | system |
-| test.c:21:3:21:8 | call to system | Call to banned function $@. | test.c:4:5:4:10 | system | system |
+| test.c:6:3:6:8 | call to system | Call to banned function system. |
+| test.c:14:3:14:8 | call to system | Call to banned function system. |
+| test.c:15:3:15:8 | call to system | Call to banned function system. |
+| test.c:16:3:16:8 | call to system | Call to banned function system. |
+| test.c:17:3:17:8 | call to system | Call to banned function system. |

c/misra/test/rules/RULE-21-21/SystemOfStdlibhUsed.testref

@@ -1,9 +1,5 @@
-typedef struct _FILE FILE;
-#define NULL (void *)0
-
-int system(const char *);
-void abort(void);
-FILE *popen(const char *, const char *);
+#include <stdio.h>
+#include <stdlib.h>
 
 void f1(const char *p1) {
   FILE *l1;