Reverse the condition on UCLIBC_HAS_MMU to build __exec_alloc.o,
which is only needed on systems without an MMU.

--- uClibc-0.9.26/libc/unistd/Makefile.orig	2004-01-11 21:19:16.175787426 +0100
+++ uClibc-0.9.26/libc/unistd/Makefile	2004-01-11 21:17:45.100852700 +0100
@@ -29,6 +29,7 @@
 
 ifeq ($(strip $(UCLIBC_HAS_MMU)),y)
 	CSRC += daemon.c
+else
 	MOBJ1 += __exec_alloc.o
 endif