random: Adjust the number of loops when initializing

commit 2dac8e54 upstream.

When we are initializing using arch_get_random_long() we only need to
loop enough times to touch all the bytes in the buffer; using
poolwords for that does twice the number of operations necessary on a
64-bit machine, since in the random number generator code "word" means
32 bits.
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Link: http://lkml.kernel.org/r/1324589281-31931-1-git-send-email-tytso@mit.eduSigned-off-by: Ben Hutchings <ben@decadent.org.uk>

drivers/char/random.c

@@ -975,7 +975,7 @@ static void init_std_data(struct entropy_store *r)
 
 	now = ktime_get_real();
 	mix_pool_bytes(r, &now, sizeof(now));
-	for (i = r->poolinfo->poolwords; i; i--) {
+	for (i = r->poolinfo->POOLBYTES; i > 0; i -= sizeof flags) {
 		if (!arch_get_random_long(&flags))
 			break;
 		mix_pool_bytes(r, &flags, sizeof(flags));