buddy: Check zalloc() return value
All callers of buddy_create() are correctly checking return value.
Found by static analysis
Fixes:
@@ -286,6 +286,8 @@ struct buddy *buddy_create(unsigned int max_order)
bsize = BITMAP_BYTES(1u << (max_order + 1));
b = zalloc(sizeof(struct buddy) + bsize);
+ if (!b)
+ return NULL;
b->max_order = max_order;
BUDDY_NOISE("Map @%p, size: %d bytes\n", b->map, bsize);
