monitor: request-handler: Fix build error

monitor: request-handler: Fix build error

Fix the following build error by using the proper output type
when printing the error log.

45s] /home/abuild/rpmbuild/BUILD/pass-2.0.0/src/monitor/request-handler.c:295:31: note: format string is defined here
[   45s]   295 |   _E("failed to set flag to %lx, client(%d) | res:name(%s)id(%d)\n",
[   45s]       |                             ~~^
[   45s]       |                               |
[   45s]       |                               long unsigned int
[   45s]       |                             %llx

Change-Id: I401b2b912ed71d40b8e4a0f06d42d6b9b01c4837
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>