manager: use proper format for integers (-Wformat)

Properly print signed and unsigned integers.  This fixes warnings like:

    In file included from src/near.h:36,
                     from src/manager.c:34:
    src/manager.c: In function ‘__near_manager_adapter_add’:
    ./include/near/log.h:45:14: error: format ‘%d’ expects argument of type ‘int’, but argument 4 has type ‘uint32_t’ {aka ‘unsigned int’} [-Werror=format=]
       45 |   near_debug("%s:%s() " fmt, \
          |              ^~~~~~~~~~
    src/manager.c:45:2: note: in expansion of macro ‘DBG’
       45 |  DBG("idx %d", idx);
          |  ^~~

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
1 file changed