detect/multi-tentancy: minor format string fixes

detect/multi-tentancy: minor format string fixes

cppcheck:

src/detect-engine.c:3643:5: warning: %d in format string (no. 1) requires 'int' but the argument type is 'unsigned int'. [invalidPrintfArgType_sint]
    snprintf(prefix, sizeof(prefix), "multi-detect.%d", tenant_id);
    ^
src/detect-engine.c:3707:5: warning: %d in format string (no. 1) requires 'int' but the argument type is 'unsigned int'. [invalidPrintfArgType_sint]
    snprintf(prefix, sizeof(prefix), "multi-detect.%d.reload.%d", tenant_id, reload_cnt);
    ^
src/detect-engine.c:4086:17: warning: %d in format string (no. 1) requires 'int' but the argument type is 'unsigned int'. [invalidPrintfArgType_sint]
                snprintf(prefix, sizeof(prefix), "multi-detect.%d", tenant_id);
                ^

Bug: #5291.
(cherry picked from commit 4fcb8740e7b98eee1b5e65bd66045c9440cef8b6)