This makes OBJECT_PATH_FOREACH_PREFIX consistent with PATH_FOREACH_PREFIX
and also fixes 7 alerts reported by LGTM at
https://lgtm.com/projects/g/systemd/systemd/snapshot/
ac0a08700344a5690803df8dd80e8bb5013184a5/files/src/libsystemd/sd-bus/bus-objects.c?sort=name&dir=ASC&mode=heatmap&showExcluded=true#V1383
#define OBJECT_PATH_FOREACH_PREFIX(prefix, path) \
for (char *_slash = ({ strcpy((prefix), (path)); streq((prefix), "/") ? NULL : strrchr((prefix), '/'); }) ; \
- _slash && !(_slash[(_slash) == (prefix)] = 0); \
+ _slash && ((_slash[(_slash) == (prefix)] = 0), true); \
_slash = streq((prefix), "/") ? NULL : strrchr((prefix), '/'))
/* If we are invoking callbacks of a bus object, ensure unreffing the