mm: use zone lock guard in take_page_off_buddy()

mm: use zone lock guard in take_page_off_buddy()

Use spinlock_irqsave zone lock guard in take_page_off_buddy() to replace
the explicit lock/unlock pattern with automatic scope-based cleanup.

This also allows to return directly from the loop, removing the 'ret'
variable.

Link: https://lore.kernel.org/a981721632a981f148c63e3f7df3d1116a0c3f6d.1777462630.git.d@ilvokhin.com
Signed-off-by: Dmitry Ilvokhin <d@ilvokhin.com>
Suggested-by: Steven Rostedt <rostedt@goodmis.org>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Brendan Jackman <jackmanb@google.com>
Cc: David Hildenbrand <david@kernel.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Lorenzo Stoakes <ljs@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@kernel.org>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>