add comment explaining why load_command search works

util/fipstools/inject_hash/macho_parser/macho_parser.c

@@ -56,6 +56,7 @@ int read_macho_file(const char *filename, machofile *macho) {
     int const_found = 0;
     int symtab_found = 0;
 
+    // mach-o/loader.h explains that cmdsize (and by extension sizeofcmds) must be a multiple of 8 on 64-bit systems. struct load_command will always be 8 bytes.
     for (uint32_t i = 0; i < macho->macho_header.sizeofcmds / sizeof(struct load_command); i += load_commands[i].cmdsize / sizeof(struct load_command)) {
         if (load_commands[i].cmd == LC_SEGMENT_64) {
             struct segment_command_64 *segment = (struct segment_command_64 *)&load_commands[i];