ChangeLog, e2fsck.c, pass4.c, problem.h, unix.c:

ChangeLog, e2fsck.c, pass4.c, problem.h, unix.c:
  pass4.c (e2fsck_pass4): Clear inode_imagic_map after freeing it, to
  	prevent it from getting freed twice.
  unix.c (main): Close the filesystem before freeing the context, so
  	that in the event of a free()-related segmentation violation, the
  	filesystem is properly closed and written out.
  e2fsck.c (e2fsck_reset_context): When freeing ctx->inode_reg_map, we
  	weren't zero'ing ctx->inode_reg_map, which could cause a segfault
  	later on in the e2fsck run.
  problem.h (PR_2_SPLIT_DOT): Fix excess zero in problem code (now
  	matches the standard convention).