From: Bart Samwel <bart@samwel.tk>

This patch from Micha Feigin fixes some bugs in the earlier reiserfs 
commit default patch. The changelog:

* If you remounted without any commit=NNN option, it would assume commit=0
  and restore the defaults.  This patch makes it leave the current state alone
  if you don't pass commit=NNN.

* Added range check for cast from unsigned long to unsigned int.