ck_sequence: relax sequence increment from atomic to regular store

The atomicity of the sequence number's increment is unnecessary, since
there should be only one writer at any given time. Fix it by changing
it for a regular increment + store.

Signed-off-by: Emilio G. Cota <cota@braap.org>

include/ck_sequence.h

@@ -101,7 +101,7 @@ ck_sequence_write_begin(struct ck_sequence *sq)
 	 * Increment the sequence to an odd number to indicate
 	 * the beginning of a write update.
 	 */
-	ck_pr_inc_uint(&sq->sequence);
+	ck_pr_store_uint(&sq->sequence, sq->sequence + 1);
 	ck_pr_fence_store();
 	return;
 }
@@ -118,7 +118,7 @@ ck_sequence_write_end(struct ck_sequence *sq)
 	 * completion of a write update.
 	 */
 	ck_pr_fence_store();
-	ck_pr_inc_uint(&sq->sequence);
+	ck_pr_store_uint(&sq->sequence, sq->sequence + 1);
 	return;
 }