Fix issues detected by Coverity (#1154)

wasm_c_api.c: add more checks, fix LOG_WARNING invalid specifier
aot_emit_aot_file: fix strncpy max size length to copy
posix.c: fix potential socket not close issue
wasm-c-api samples: add return value checks for fseek/ftell
cJSON.c: remove dead code

core/iwasm/compilation/aot_emit_aot_file.c

@@ -2104,7 +2104,7 @@ aot_resolve_target_info(AOTCompContext *comp_ctx, AOTObjectData *obj_data)
     }
 
     strncpy(obj_data->target_info.arch, comp_ctx->target_arch,
-            sizeof(obj_data->target_info.arch));
+            sizeof(obj_data->target_info.arch) - 1);
 
     return true;
 }