misra.py: Fix false positive for rule 15.6 (#2631)

addons/misra.py

@@ -1950,7 +1950,7 @@ class MisraChecker:
                 if token.str.startswith('//') or token.str.startswith('/*'):
                     continue
                 state = 0
-                if token.str != '{':
+                if token.str not in ('{', '#'):
                     self.reportError(tok1, 15, 6)
 
     def misra_15_7(self, data):

addons/test/misra/misra-test.c

@@ -739,6 +739,14 @@ void misra_15_6() {
   (void)0;
 #endif
 
+#if A > 0x42
+  if (true) {
+    (void)0;
+  }
+  if (true)
+#endif
+  { (void)0; } // no-warning
+
   do {} while (x<0); // no-warning
 }