Building without thread support

[Peter Kjellerstedt]

While I was looking for a another problem, I tried to build 
the latest svn version of uClibc without thread support.
This failed on the first file it tried to compile, and I had
to apply the following patch to make it compile.
Any comments, or should I go ahead and commit it?

Index: libc/sysdeps/linux/common/bits/uClibc_errno.h
===================================================================
--- libc/sysdeps/linux/common/bits/uClibc_errno.h	(revision 16185)
+++ libc/sysdeps/linux/common/bits/uClibc_errno.h	(working copy)
@@ -31,10 +31,12 @@
 	attribute_hidden
 # endif
 ;
+#if defined __UCLIBC_HAS_THREADS__
 #include <tls.h>
 #if USE___THREAD
 libc_hidden_proto(__errno_location)
 #endif
+#endif
 
 /* We now need a declaration of the `errno' variable.  */
 # ifndef __UCLIBC_HAS_THREADS__

//Peter