xtensa: ISS: Use kmalloc_array() in simdisk_init()

* A multiplication for the size determination of a memory allocation
  indicated that an array data structure should be processed.
  Thus use the corresponding function "kmalloc_array".

  This issue was detected by using the Coccinelle software.

* Replace the specification of a data type by a pointer dereference
  to make the corresponding size determination a bit safer according to
  the Linux coding style convention.
Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>

arch/xtensa/platforms/iss/simdisk.c

@@ -317,8 +317,7 @@ static int __init simdisk_init(void)
 	if (simdisk_count > MAX_SIMDISK_COUNT)
 		simdisk_count = MAX_SIMDISK_COUNT;
 
-	sddev = kmalloc(simdisk_count * sizeof(struct simdisk),
-			GFP_KERNEL);
+	sddev = kmalloc_array(simdisk_count, sizeof(*sddev), GFP_KERNEL);
 	if (sddev == NULL)
 		goto out_unregister;