update unifdef causing partial header generation and

[Vineet Gupta]

I've been testing the master with ARC support and it seems commit 2a021ae81c36
"buildsys: update unifdef" sometimes generates a partial uClibc_config.h and other
false warnings for headers as below.

--------------------------->8----------------------
  INSTALL include ->
/home/vineetg/arc/old_gnu/tmp-install-uclibc-15655/arc-linux-uclibc/include
unifdef: include/bits/kernel_sigaction.h: 24: Inappropriate #endif
unifdef: output may be truncated
unifdef: include/bits/uClibc_config.h: 3: Inappropriate #endif
unifdef: output may be truncated
unifdef: include/sys/termios.h: 4: Inappropriate #endif
unifdef: output may be truncated
unifdef: include/net/ppp_defs.h: 10: Inappropriate #endif
....

--------------------------->8----------------------

Reverting it out sees to make things work. Anyone else seeing similar issues.

-Vineet