tests: Check non-matching cases for fdt_node_check_compatible()

The current tests for fdt_node_check_compatible() test that it returns true
on several matching cases, but don't test that it actually returns false on
some non-matching cases, which isn't great coverage.  Add some basic tests
to address that.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>

tests/node_check_compatible.c

@@ -45,6 +45,23 @@ static void check_compatible(const void *fdt, const char *path,
 		FAIL("%s is not compatible with \"%s\"", path, compat);
 }
 
+static void check_not_compatible(const void *fdt, const char *path,
+				 const char *compat)
+{
+	int offset, err;
+
+	offset = fdt_path_offset(fdt, path);
+	if (offset < 0)
+		FAIL("fdt_path_offset(%s): %s", path, fdt_strerror(offset));
+
+	err = fdt_node_check_compatible(fdt, offset, compat);
+	if (err < 0)
+		FAIL("fdt_node_check_compatible(%s): %s", path,
+		     fdt_strerror(err));
+	if (err == 0)
+		FAIL("%s is incorrectly compatible with \"%s\"", path, compat);
+}
+
 int main(int argc, char *argv[])
 {
 	void *fdt;
@@ -55,8 +72,10 @@ int main(int argc, char *argv[])
 	check_compatible(fdt, "/", "test_tree1");
 	check_compatible(fdt, "/subnode@1/subsubnode", "subsubnode1");
 	check_compatible(fdt, "/subnode@1/subsubnode", "subsubnode");
+	check_not_compatible(fdt, "/subnode@1/subsubnode", "subsubnode2");
 	check_compatible(fdt, "/subnode@2/subsubnode", "subsubnode2");
 	check_compatible(fdt, "/subnode@2/subsubnode", "subsubnode");
+	check_not_compatible(fdt, "/subnode@2/subsubnode", "subsubnode1");
 
 	PASS();
 }