mm: Tidy up pcp lists checks usage

check_pcp_refill() remains the same with and without CONFIG_DEBUG_VM enabled.
Remove the unnecesary guard and keep the functions inlined alongside making use
of ternary operator at check_new_pcp() to choose the return value conditionally
to achieve better code readability without compromising any functionality.

Signed-off-by: Tashfin Shakeer Rhythm <tashfinshakeerrhythm@gmail.com>

Author: Tashar02

mm/page_alloc.c

@@ -1808,26 +1808,15 @@ static inline bool free_pages_prezeroed(void)
 		page_poisoning_enabled()) || want_init_on_free();
 }
 
-#ifdef CONFIG_DEBUG_VM
-static bool check_pcp_refill(struct page *page)
-{
-	return false;
-}
-
-static bool check_new_pcp(struct page *page)
-{
-	return check_new_page(page);
-}
-#else
 static inline bool check_pcp_refill(struct page *page)
 {
 	return false;
 }
+
 static inline bool check_new_pcp(struct page *page)
 {
-	return false;
+	return IS_ENABLED(CONFIG_DEBUG_VM) ? check_new_page(page) : false;
 }
-#endif /* CONFIG_DEBUG_VM */
 
 static bool check_new_pages(struct page *page, unsigned int order)
 {