drivers/block: Use DIV_ROUND_UP

The kernel.h macro DIV_ROUND_UP performs the computation (((n) + (d) - 1) /
(d)) but is perhaps more readable.

An extract of the semantic patch that makes this change is as follows:
(http://www.emn.fr/x-info/coccinelle/)

// <smpl>
@haskernel@
@@

#include <linux/kernel.h>

@depends on haskernel@
expression n,d;
@@

(
- (n + d - 1) / d
+ DIV_ROUND_UP(n,d)
|
- (n + (d - 1)) / d
+ DIV_ROUND_UP(n,d)
)

@depends on haskernel@
expression n,d;
@@

- DIV_ROUND_UP((n),d)
+ DIV_ROUND_UP(n,d)

@depends on haskernel@
expression n,d;
@@

- DIV_ROUND_UP(n,(d))
+ DIV_ROUND_UP(n,d)
// </smpl>

Signed-off-by: Julia Lawall <julia@diku.dk>
Cc: <mike.miller@hp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
diff --git a/drivers/block/cciss.c b/drivers/block/cciss.c
index b73116e..1e1f915 100644
--- a/drivers/block/cciss.c
+++ b/drivers/block/cciss.c
@@ -3460,8 +3460,8 @@
 	       hba[i]->intr[SIMPLE_MODE_INT], dac ? "" : " not");
 
 	hba[i]->cmd_pool_bits =
-	    kmalloc(((hba[i]->nr_cmds + BITS_PER_LONG -
-		      1) / BITS_PER_LONG) * sizeof(unsigned long), GFP_KERNEL);
+	    kmalloc(DIV_ROUND_UP(hba[i]->nr_cmds, BITS_PER_LONG)
+			* sizeof(unsigned long), GFP_KERNEL);
 	hba[i]->cmd_pool = (CommandList_struct *)
 	    pci_alloc_consistent(hba[i]->pdev,
 		    hba[i]->nr_cmds * sizeof(CommandList_struct),
@@ -3493,8 +3493,8 @@
 	/* command and error info recs zeroed out before
 	   they are used */
 	memset(hba[i]->cmd_pool_bits, 0,
-	       ((hba[i]->nr_cmds + BITS_PER_LONG -
-		 1) / BITS_PER_LONG) * sizeof(unsigned long));
+	       DIV_ROUND_UP(hba[i]->nr_cmds, BITS_PER_LONG)
+			* sizeof(unsigned long));
 
 	hba[i]->num_luns = 0;
 	hba[i]->highest_lun = -1;