Convert strncpy to strlcpy

We try to avoid using strncpy() due to the ease of which it can
be misused.  Convert this callsite to use strlcpy() instead to
match similar codepaths in this file.

Suggested-by: Peter Eisentraut <peter@eisentraut.org>
Discussion: https://postgr.es/m/2a796830-de2d-4030-b480-d673f6cc5d94@eisentraut.org

src/backend/utils/mmgr/mcxt.c

@@ -1664,8 +1664,7 @@ ProcessGetMemoryContextInterrupt(void)
 			num_individual_stats = context_id + 1;
 			meminfo[max_stats - 1].name = dsa_allocate(MemoryStatsDsaArea, namelen + 1);
 			nameptr = dsa_get_address(MemoryStatsDsaArea, meminfo[max_stats - 1].name);
-			strncpy(nameptr, "Remaining Totals", namelen);
-			nameptr[namelen] = '\0';
+			strlcpy(nameptr, "Remaining Totals", namelen + 1);
 			meminfo[max_stats - 1].ident = InvalidDsaPointer;
 			meminfo[max_stats - 1].path = InvalidDsaPointer;
 			meminfo[max_stats - 1].type = 0;