Fix function spelling mistake in iphc_decompress.c

lowpan_contex_get_by_id -> lowpan_context_get_by_id

Author: DavidLin1577

features/nanostack/sal-stack-nanostack/source/6LoWPAN/IPHC_Decode/iphc_decompress.c

@@ -249,7 +249,7 @@ static bool decompress_mc_addr(const lowpan_context_list_t *context_list, uint8_
             *in_ptr = in;
             return true;
         case HC_48BIT_CONTEXT_MULTICAST: {
-            lowpan_context_t *ctx = lowpan_contex_get_by_id(context_list, context);
+            lowpan_context_t *ctx = lowpan_context_get_by_id(context_list, context);
             if (!ctx) {
                 return false;
             }
@@ -312,7 +312,7 @@ static bool decompress_addr(const lowpan_context_list_t *context_list, uint8_t *
     }
 
     if (mode & HC_DSTADR_COMP) {
-        lowpan_context_t *ctx = lowpan_contex_get_by_id(context_list, context);
+        lowpan_context_t *ctx = lowpan_context_get_by_id(context_list, context);
         if (!ctx) {
             return false;
         }