style: add braces around if/while statements

Per guidelines, all statements should have braces around them. We do not
have a CI check for this, so a few went in unnoticed.

Signed-off-by: Anas Nashif <anas.nashif@intel.com>

subsys/cpp/cpp_virtual.c

@@ -20,6 +20,5 @@
 void __cxa_pure_virtual(void)
 {
 	while (1) {
-		;
 	}
 }