small cosmetic changes.

I prefer `i++` style unless absolutely necessary.

src/codedump.c

@@ -102,7 +102,7 @@ codedump(mrb_state *mrb, const mrb_irep *irep)
     int i;
     int head = FALSE;
 
-    for (i = 1; i < irep->nlocals; ++i) {
+    for (i = 1; i < irep->nlocals; i++) {
       char const *s = mrb_sym_dump(mrb, irep->lv[i - 1]);
       if (s) {
         if (!head) {
@@ -118,7 +118,7 @@ codedump(mrb_state *mrb, const mrb_irep *irep)
     int i = irep->clen;
     const struct mrb_irep_catch_handler *e = mrb_irep_catch_handler_table(irep);
 
-    for (; i > 0; i --, e ++) {
+    for (; i > 0; i--,e++) {
       uint32_t begin = mrb_irep_catch_handler_unpack(e->begin);
       uint32_t end = mrb_irep_catch_handler_unpack(e->end);
       uint32_t target = mrb_irep_catch_handler_unpack(e->target);

src/debug.c

@@ -202,7 +202,7 @@ mrb_debug_info_append_file(mrb_state *mrb, mrb_irep_debug_info *d,
   size_t packed_size = 0;
   uint8_t *p, *pend;
 
-  for (i = 0; i < file_pc_count; ++i) {
+  for (i = 0; i < file_pc_count; i++) {
     if (lines[start_pos + i] == prev_line) continue;
     packed_size += mrb_packed_int_len(start_pos+i-prev_pc);
     prev_pc = start_pos+i;
@@ -212,7 +212,7 @@ mrb_debug_info_append_file(mrb_state *mrb, mrb_irep_debug_info *d,
   f->lines.packed_map = p = (uint8_t*)mrb_malloc(mrb, packed_size);
   pend = p + packed_size;
   prev_line = 0; prev_pc = 0;
-  for (i = 0; i < file_pc_count; ++i) {
+  for (i = 0; i < file_pc_count; i++) {
     if (lines[start_pos + i] == prev_line) continue;
     p += mrb_packed_int_encode(start_pos+i-prev_pc, p, pend);
     prev_pc = start_pos + i;
@@ -232,7 +232,7 @@ mrb_debug_info_free(mrb_state *mrb, mrb_irep_debug_info *d)
   if (!d) { return; }
 
   if (d->files) {
-    for (i = 0; i < d->flen; ++i) {
+    for (i = 0; i < d->flen; i++) {
       if (d->files[i]) {
         mrb_free(mrb, d->files[i]->lines.ptr);
         mrb_free(mrb, d->files[i]);

src/error.c

@@ -278,7 +278,7 @@ mrb_vformat(mrb_state *mrb, const char *format, va_list ap)
     if (c == '%') {
       if (*p == '!') {
         inspect = TRUE;
-        ++p;
+        p++;
       }
       if (!*p) break;
       switch (*p) {