maint: avoid new unused-macro warnings from gcc
* src/ls.c (ASSERT_MATCHING_DEV_INO): Comment-out unused definition,
to match commented-out use.
* src/install.c (INITIAL_HASH_MODULE, INITIAL_ENTRY_TAB_SIZE):
(READ_SIZE): Remove definitions of unused macros.
* src/mv.c (INITIAL_HASH_MODULE, INITIAL_ENTRY_TAB_SIZE): Likewise.
* src/dd.c (max): Likewise.
* src/expand.c (OUTPUT_BLOCK): Likewise.
* src/csplit.c (ALLOC_SIZE): Likewise.
* src/pr.c (NULLCOL): Likewise.
* src/ptx.c (Sword): Likewise.
* src/unexpand.c (OUTPUT_BLOCK): Likewise.
* src/factor.c (NDEBUG): Likewise.