[danger] broken libc.so on stable

[Kostik Belousov]

Revision 1.48.8.1 of lib/libc/stdlib/Makefile.inc removed calloc.c from the list
of the source files. As result, freshly built libc does not contain
calloc symbol,
that completely broke my stable box. The only solution for me was booting
from 6.0-RELEASE disc1 and copying libc.so.6 into /lib. After that, manually
adding calloc.c to the MISRCS in Makefile.inc and installing libc put
the system in order.

I suppose that this is simple MFC error. Please, correct it before big
havoc hit the
stable boxes !

Best regards,
Kostik Belousov