Defines starting with `l' in common

• LAST_MODE_OF_OPERATION common/crypto.h:103
• LAST_PRF_ID common/crypto.h:64
• LEGACY_VOL_IV_SIZE common/crypto.h:46
• lp common/gfmul.c:149
• lp_inc common/gfmul.c:150
• LRW_TEST_COUNT common/tests.c:580