sysutils/qdirstat: fix build on armv7
The operator << of the LogStream class is used to output numerical
values among other things. The port tries to output a value of type
unsigned long long on armv7, while presumably not doing so on other
platforms. Add an overload for unsigned long long to fix the build.
Approved by: portmgr (build fix blanket)
MFH: 2026Q1