scripts/gdb: If not building expat for gdb, disable

--with-expat=yes is unconditionally passed to the gdb configure
stage, instead of respecting the ${do_expat} decision.

Disable if not needed. Prevents error building canadian cross;

configure: error: expat is missing or unusable

Where configure stage fails to find expat on the host compiler.

Signed-off-by: "David Holsgrove" <david.holsgrove@xilinx.com>
Signed-off-by: Bryan Hundven <bryanhundven@gmail.com>
Message-Id: <4c4410a2a8aab24a29c5.1349244128@localhost.localdomain>
PatchWork-Id: 188711

--- glibc-2_9.orig/nptl/init.c	2007-10-15 22:25:25.000000000 +0200

+++ glibc-2_9/nptl/init.c	2010-08-18 10:46:06.109098646 +0200

@@ -236,7 +236,7 @@

 /* This can be set by the debugger before initialization is complete.  */

-static bool __nptl_initial_report_events;

+static bool __nptl_initial_report_events __attribute_used__;

 void

 __pthread_initialize_minimal_internal (void)