Check and propagate error

per_put_few_bits should be checked for errors.
Checked return, fund by coverity.

Signed-off-by: Simo Sorce <simo@redhat.com>
diff --git a/skeletons/per_support.c b/skeletons/per_support.c
index 14b4c4c..635db40 100644
--- a/skeletons/per_support.c
+++ b/skeletons/per_support.c
@@ -394,8 +394,8 @@
 		buf[2] = bits >> 8,
 		buf[3] = bits;
 	else {
-		per_put_few_bits(po, bits >> (obits - 24), 24);
-		per_put_few_bits(po, bits, obits - 24);
+		if(per_put_few_bits(po, bits >> (obits - 24), 24)) return -1;
+		if(per_put_few_bits(po, bits, obits - 24)) return -1;
 	}
 
 	ASN_DEBUG("[PER out %u/%x => %02x buf+%ld]",