Fix warnings from new version of clang tidy.

Change-Id: I2c85c8addd2bec83fa3796bb3ca8e87f5523a6fc
diff --git a/test/linux/linux.c b/test/linux/linux.c
index f0798e9..beffe8e 100644
--- a/test/linux/linux.c
+++ b/test/linux/linux.c
@@ -34,12 +34,12 @@
 
 static int finit_module(int fd, const char *param_values, int flags)
 {
-	return syscall(SYS_finit_module, fd, param_values, flags);
+	return (int)syscall(SYS_finit_module, fd, param_values, flags);
 }
 
 static int delete_module(const char *name, int flags)
 {
-	return syscall(SYS_delete_module, name, flags);
+	return (int)syscall(SYS_delete_module, name, flags);
 }
 
 static void insmod_hafnium(void)