[toolchain] uClibc: fix errno access in pthreads (#8166, #8177)

Reading errno within pthreads always resulted in 0 breaking various programs
like transmission and collectd. This patch is not 100% thread safe but it brings
back threading into a usable state for now.


git-svn-id: svn://svn.openwrt.org/openwrt/trunk@23905 3c298f89-4303-0410-b956-a3cf2f4a3e73

toolchain/uClibc/patches-0.9.31/904-pthread_errno_fix.patch

@@ -0,0 +1,18 @@
+--- a/libpthread/linuxthreads.old/errno.c
++++ b/libpthread/linuxthreads.old/errno.c
+@@ -22,6 +22,7 @@
+ #include "internals.h"
+ #include <stdio.h>
+ 
++libpthread_hidden_proto(__errno_location)
+ int *
+ __errno_location (void)
+ {
+@@ -29,6 +30,7 @@ __errno_location (void)
+   return THREAD_GETMEM (self, p_errnop);
+ }
+ 
++libpthread_hidden_proto(__h_errno_location)
+ int *
+ __h_errno_location (void)
+ {