socl/examples: calling clGetPlatformIDs with NULL as last parameter fail on apple systems

socl/examples/basic/basic.c

@@ -91,7 +91,7 @@ int main(int UNUSED(argc), char** UNUSED(argv)) {
       exit(77);
    }
 
-   err = clGetPlatformIDs(sizeof(platforms)/sizeof(cl_platform_id), platforms, NULL);
+   err = clGetPlatformIDs(sizeof(platforms)/sizeof(cl_platform_id), platforms, &num_platforms);
    check(err, "clGetPlatformIDs");
 
    int platform_idx = -1;

socl/examples/mansched/mansched.c

@@ -80,7 +80,7 @@ int main(int UNUSED(argc), char** UNUSED(argv)) {
       printf("No OpenCL platform found.\n");
       exit(77);
    }
-   err = clGetPlatformIDs(sizeof(platforms)/sizeof(cl_platform_id), platforms, NULL);
+   err = clGetPlatformIDs(sizeof(platforms)/sizeof(cl_platform_id), platforms, &num_platforms);
    check(err, "clGetPlatformIDs");
 
    printf("Querying devices...\n");

socl/examples/testmap/testmap.c

@@ -83,7 +83,7 @@ int main(int UNUSED(argc), char** UNUSED(argv)) {
       exit(77);
    }
 
-   err = clGetPlatformIDs(sizeof(platforms)/sizeof(cl_platform_id), platforms, NULL);
+   err = clGetPlatformIDs(sizeof(platforms)/sizeof(cl_platform_id), platforms, &num_platforms);
    check(err, "clGetPlatformIDs");
 
    int platform_idx = -1;