Fix warnings from MIPS soft-float _FPU_GETCW

["Joseph S. Myers" <joseph@codesourcery.com>]

Testing for MIPS soft-float showed up compile warnings ("statement
with no effect") in setfpucw.c arising from the soft-float definition
of _FPU_GETCW just being "0".  I've applied this patch to make the
definition actually store 0 in cw, and correspondingly to make
_FPU_SETCW use cw by casting the value to (void), to make these
soft-float definitions better at avoiding warnings from use using
these macros.

2012-12-04  Joseph Myers  <joseph@codesourcery.com>

	* sysdeps/mips/fpu_control.h [__mips_soft_float] (_FPU_GETCW):
	Define to set cw to 0, now just to plain "0" as a statement.
	[__mips_soft_float] (_FPU_SETCW): Define to (void) (cw), rather
	than doing nothing with cw.

diff --git a/ports/sysdeps/mips/fpu_control.h b/ports/sysdeps/mips/fpu_control.h
index 7307d03..acf794c 100644
--- a/ports/sysdeps/mips/fpu_control.h
+++ b/ports/sysdeps/mips/fpu_control.h
@@ -1,6 +1,5 @@
 /* FPU control word bits.  Mips version.
-   Copyright (C) 1996, 1997, 1998, 1999, 2000, 2006, 2008
-   Free Software Foundation, Inc.
+   Copyright (C) 1996-2012 Free Software Foundation, Inc.
    This file is part of the GNU C Library.
    Contributed by Olaf Flebbe and Ralf Baechle.
 
@@ -63,8 +62,8 @@
 #define _FPU_RESERVED 0xffffffff
 #define _FPU_DEFAULT  0x00000000
 typedef unsigned int fpu_control_t;
-#define _FPU_GETCW(cw) 0
-#define _FPU_SETCW(cw) do { } while (0)
+#define _FPU_GETCW(cw) (cw) = 0
+#define _FPU_SETCW(cw) (void) (cw)
 extern fpu_control_t __fpu_control;
 
 #else /* __mips_soft_float */

-- 
Joseph S. Myers
joseph@codesourcery.com