[ARM] 3758/1: Preserve signalling NaNs in conversion

Patch from Daniel Jacobowitz

The fcvtds and fcvtsd instructions were generating a qnan bit pattern
for both quiet and signalling NaNs.

Signed-off-by: Daniel Jacobowitz <dan@codesourcery.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
diff --git a/arch/arm/vfp/vfpsingle.c b/arch/arm/vfp/vfpsingle.c
index 5bbd5d1..78d7cac 100644
--- a/arch/arm/vfp/vfpsingle.c
+++ b/arch/arm/vfp/vfpsingle.c
@@ -506,7 +506,7 @@
 	 */
 	if (tm & (VFP_INFINITY|VFP_NAN)) {
 		vdd.exponent = 2047;
-		if (tm & VFP_NAN)
+		if (tm == VFP_QNAN)
 			vdd.significand |= VFP_DOUBLE_SIGNIFICAND_QNAN;
 		goto pack_nan;
 	} else if (tm & VFP_ZERO)