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

test-tools/host-tool/external/cJSON/cJSON.c

@@ -1113,10 +1113,6 @@ fail:
         hooks->deallocate(buffer->buffer);
     }
 
-    if (printed != NULL) {
-        hooks->deallocate(printed);
-    }
-
     return NULL;
 }