sprandom: relax power of 2 block size requirement

There is no a priori reason why the SPRandom approach cannot work with
block sizes that are not a power of 2. Lift the constraint that allows
only power of 2 block sizes when sprandom is enabled.

This allows sprandom to be used when devices are formatted in extended
LBA (DIF) mode with 520- or 4160-byte sectors.

Signed-off-by: Vincent Fu <vincent.fu@samsung.com>

sprandom.c

diff --git a/sprandom.c b/sprandom.c
index 429a775..63eb200 100644
--- a/sprandom.c
+++ b/sprandom.c
@@ -533,7 +533,7 @@
 	uint64_t size;
 
 	size = logical_sz + ceil((double)logical_sz * over_provisioning);
-	return (size + (align_bs - 1)) & ~(align_bs - 1);
+	return size - (size % align_bs);
 }
 
 /**
@@ -840,12 +840,6 @@
 	if (!td->o.sprandom)
 		return 0;
 
-	if (!is_power_of_2(align_bs)) {
-		log_err("fio: sprandom: bs [%"PRIu64"] should be power of 2",
-			align_bs);
-		return -EINVAL;
-	}
-
 	info = calloc(1, sizeof(*info));
 	if (!info)
 		return -ENOMEM;