Fix warning introduced in 5c279a6d350.

Fix warning introduced in 5c279a6d350.

Change two macros to be static inline functions instead to keep the
data type consistent. This avoids a "comparison is always true"
warning that was occurring with -Wtype-limits. In the process, change
the names to look less like macros.

Discussion: https://postgr.es/m/20220407063505[email protected]