Remove extraneous parens around return arguments.

This resolves #540.

test/unit/prof_idump.c

@@ -24,7 +24,7 @@ prof_dump_open_intercept(bool propagate_err, const char *filename) {
 	fd = open("/dev/null", O_WRONLY);
 	assert_d_ne(fd, -1, "Unexpected open() failure");
 
-	return (fd);
+	return fd;
 }
 
 TEST_BEGIN(test_idump) {
@@ -50,6 +50,6 @@ TEST_END
 
 int
 main(void) {
-	return (test(
-	    test_idump));
+	return test(
+	    test_idump);
 }