8362162: Use bool for caller of os::must_commit_stack_guard_pages()

Reviewed-by: shade, kbarrett

Author: albertnetymk

src/hotspot/share/runtime/stackOverflow.cpp

@@ -89,7 +89,7 @@ void StackOverflow::create_stack_guard_pages() {
   assert(is_aligned(low_addr, os::vm_page_size()), "Stack base should be the start of a page");
   assert(is_aligned(len, os::vm_page_size()), "Stack size should be a multiple of page size");
 
-  int must_commit = os::must_commit_stack_guard_pages();
+  bool must_commit = os::must_commit_stack_guard_pages();
   // warning("Guarding at " PTR_FORMAT " for len %zu\n", low_addr, len);
 
   if (must_commit && !os::create_stack_guard_pages((char *) low_addr, len)) {