rlc: Fix memset(0) on object with no trivial copy-assignment

As warned by gcc 8.1.0, the cs field is a class (GprsCodingScheme) and
should not be memset.

Change-Id: Id742f82aa856e696b5fb414991dfd0883d0ac7fe
diff --git a/src/rlc.cpp b/src/rlc.cpp
index a82f550..ee88bd9 100644
--- a/src/rlc.cpp
+++ b/src/rlc.cpp
@@ -326,11 +326,18 @@
 	unsigned int i;
 	unsigned int padding_bits = with_padding ? cs.optionalPaddingBits() : 0;
 
-	memset(rlc, 0, sizeof(*rlc));
-
 	rlc->cs = cs;
-	rlc->with_padding = with_padding;
+	rlc->r = 0;
+	rlc->si = 0;
+	rlc->tfi = 0;
+	rlc->cps = 0;
+	rlc->rsb = 0;
+	rlc->usf = 0;
+	rlc->es_p = 0;
+	rlc->rrbp = 0;
+	rlc->pr = 0;
 	rlc->num_data_blocks = cs.numDataBlocks();
+	rlc->with_padding = with_padding;
 
 	OSMO_ASSERT(rlc->num_data_blocks <= ARRAY_SIZE(rlc->block_info));