CPP: Fix false positive.

cpp/ql/src/Likely Bugs/Conversion/ArrayArgSizeMismatch.ql

@@ -17,6 +17,7 @@ where f = c.getTarget() and
         b = paramType.getArraySize() and
         argType.getBaseType().getSize() = paramType.getBaseType().getSize() and
         a < b and
+        a > 0 and
         // filter out results for inconsistent declarations
         strictcount(f.getParameter(i).getType().getSize()) = 1
 select c.getArgument(i), "Array of size " + a +

cpp/ql/test/query-tests/Likely Bugs/Conversion/ArrayArgSizeMismatch/ArrayArgSizeMismatch.expected

@@ -1,2 +1 @@
 | test.cpp:24:4:24:7 | arr3 | Array of size 3 passed to $@ which expects an array of size 4. | test.cpp:8:6:8:6 | g | g |
-| test.cpp:40:9:40:12 | data | Array of size 0 passed to $@ which expects an array of size 4. | test.cpp:9:6:9:6 | h | h |

cpp/ql/test/query-tests/Likely Bugs/Conversion/ArrayArgSizeMismatch/test.cpp

@@ -37,7 +37,7 @@ void test(float f3[3], float f4[4], float f5[5], float *fp)
 		ms = (myStruct *)malloc(sizeof(myStruct) + (4 * sizeof(float)));
 		ms->num  = 4;
 		ms->data[0] = ms->data[1] = ms->data[2] = ms->data[3] = 0;
-		h(ms->data); // GOOD [FALSE POSITIVE]
+		h(ms->data); // GOOD
 	}
 	
 	{