net: lwm2m: fix formatter reader/writer initialization syntax

For ease of maintenance, let's swap the reader/writer initialization
syntax to:
.put_begin = put_begin,
.put_end = put_end,
...

This way we only assign used fields and adding new ones later is
less error prone.

Signed-off-by: Michael Scott <[email protected]>

Author: mike-scott

subsys/net/lib/lwm2m/lwm2m_rw_json.c

@@ -506,23 +506,18 @@ static size_t put_bool(struct lwm2m_output_context *out,
 }
 
 const struct lwm2m_writer json_writer = {
-	put_begin,
-	put_end,
-	NULL,
-	NULL,
-	NULL,
-	NULL,
-	put_begin_ri,
-	put_end_ri,
-	put_s8,
-	put_s16,
-	put_s32,
-	put_s64,
-	put_string,
-	put_float32fix,
-	put_float64fix,
-	put_bool,
-	NULL
+	.put_begin = put_begin,
+	.put_end = put_end,
+	.put_begin_ri = put_begin_ri,
+	.put_end_ri = put_end_ri,
+	.put_s8 = put_s8,
+	.put_s16 = put_s16,
+	.put_s32 = put_s32,
+	.put_s64 = put_s64,
+	.put_string = put_string,
+	.put_float32fix = put_float32fix,
+	.put_float64fix = put_float64fix,
+	.put_bool = put_bool,
 };
 
 int do_read_op_json(struct lwm2m_engine_obj *obj,

subsys/net/lib/lwm2m/lwm2m_rw_oma_tlv.c

@@ -785,33 +785,28 @@ static size_t get_opaque(struct lwm2m_input_context *in,
 }
 
 const struct lwm2m_writer oma_tlv_writer = {
-	NULL,
-	NULL,
-	put_begin_oi,
-	put_end_oi,
-	NULL,
-	NULL,
-	put_begin_ri,
-	put_end_ri,
-	put_s8,
-	put_s16,
-	put_s32,
-	put_s64,
-	put_string,
-	put_float32fix,
-	put_float64fix,
-	put_bool,
-	NULL
+	.put_begin_oi = put_begin_oi,
+	.put_end_oi = put_end_oi,
+	.put_begin_ri = put_begin_ri,
+	.put_end_ri = put_end_ri,
+	.put_s8 = put_s8,
+	.put_s16 = put_s16,
+	.put_s32 = put_s32,
+	.put_s64 = put_s64,
+	.put_string = put_string,
+	.put_float32fix = put_float32fix,
+	.put_float64fix = put_float64fix,
+	.put_bool = put_bool,
 };
 
 const struct lwm2m_reader oma_tlv_reader = {
-	get_s32,
-	get_s64,
-	get_string,
-	get_float32fix,
-	get_float64fix,
-	get_bool,
-	get_opaque
+	.get_s32 = get_s32,
+	.get_s64 = get_s64,
+	.get_string = get_string,
+	.get_float32fix = get_float32fix,
+	.get_float64fix = get_float64fix,
+	.get_bool = get_bool,
+	.get_opaque = get_opaque,
 };
 
 int do_read_op_tlv(struct lwm2m_engine_obj *obj,

subsys/net/lib/lwm2m/lwm2m_rw_plain_text.c

@@ -310,33 +310,24 @@ static size_t get_opaque(struct lwm2m_input_context *in,
 }
 
 const struct lwm2m_writer plain_text_writer = {
-	NULL,
-	NULL,
-	NULL,
-	NULL,
-	NULL,
-	NULL,
-	NULL,
-	NULL,
-	put_s8,
-	put_s16,
-	put_s32,
-	put_s64,
-	put_string,
-	put_float32fix,
-	put_float64fix,
-	put_bool,
-	NULL
+	.put_s8 = put_s8,
+	.put_s16 = put_s16,
+	.put_s32 = put_s32,
+	.put_s64 = put_s64,
+	.put_string = put_string,
+	.put_float32fix = put_float32fix,
+	.put_float64fix = put_float64fix,
+	.put_bool = put_bool,
 };
 
 const struct lwm2m_reader plain_text_reader = {
-	get_s32,
-	get_s64,
-	get_string,
-	get_float32fix,
-	get_float64fix,
-	get_bool,
-	get_opaque
+	.get_s32 = get_s32,
+	.get_s64 = get_s64,
+	.get_string = get_string,
+	.get_float32fix = get_float32fix,
+	.get_float64fix = get_float64fix,
+	.get_bool = get_bool,
+	.get_opaque = get_opaque,
 };
 
 int do_read_op_plain_text(struct lwm2m_engine_obj *obj,