Fix for loop initial declaration

[ten0s]

GNU 4.8.5 CentOS 7

/bee2/cmd/core/whereami.c:266:3: error: 'for' loop initial declarations are only allowed in C99 mode
   for (int r = 0; r < WAI_PROC_SELF_MAPS_RETRY; ++r)

[agievich]

Thanks! Actually whereami.c is third party code. It would be great if you also address this issue to the official repository of whereami: https://github.com/gpakosz/whereami.