percpu: setup_first_chunk rename schunk/dchunk to chunk

There is no need to have the static chunk and dynamic chunk be named
separately as the allocations are sequential. This preemptively solves
the misnomer problem with the base_addrs being moved up in the following
patch. It also removes a ternary operation deciding the first chunk.

Signed-off-by: Dennis Zhou <dennisszhou@gmail.com>
Reviewed-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
diff --git a/mm/percpu.c b/mm/percpu.c
index 1d2c980..e08ed61 100644
--- a/mm/percpu.c
+++ b/mm/percpu.c
@@ -1602,7 +1602,7 @@
 	static int smap[PERCPU_DYNAMIC_EARLY_SLOTS] __initdata;
 	static int dmap[PERCPU_DYNAMIC_EARLY_SLOTS] __initdata;
 	size_t size_sum = ai->static_size + ai->reserved_size + ai->dyn_size;
-	struct pcpu_chunk *schunk, *dchunk = NULL;
+	struct pcpu_chunk *chunk;
 	unsigned long *group_offsets;
 	size_t *group_sizes;
 	unsigned long *unit_off;
@@ -1720,22 +1720,22 @@
 	 */
 	start_offset = ai->static_size;
 	map_size = ai->reserved_size ?: ai->dyn_size;
-	schunk = pcpu_alloc_first_chunk(base_addr, start_offset, map_size,
-					smap, ARRAY_SIZE(smap));
+	chunk = pcpu_alloc_first_chunk(base_addr, start_offset, map_size, smap,
+				       ARRAY_SIZE(smap));
 
 	/* init dynamic chunk if necessary */
 	if (ai->reserved_size) {
-		pcpu_reserved_chunk = schunk;
+		pcpu_reserved_chunk = chunk;
 
 		start_offset = ai->static_size + ai->reserved_size;
 		map_size = ai->dyn_size;
-		dchunk = pcpu_alloc_first_chunk(base_addr, start_offset,
-						map_size, dmap,
-						ARRAY_SIZE(dmap));
+		chunk = pcpu_alloc_first_chunk(base_addr, start_offset,
+					       map_size, dmap,
+					       ARRAY_SIZE(dmap));
 	}
 
 	/* link the first chunk in */
-	pcpu_first_chunk = dchunk ?: schunk;
+	pcpu_first_chunk = chunk;
 	i = (pcpu_first_chunk->start_offset) ? 1 : 0;
 	pcpu_nr_empty_pop_pages +=
 		pcpu_count_occupied_pages(pcpu_first_chunk, i);