softfloat: Fix tp init in float32_exp2

Typo in the conversion to FloatParts64.

Fixes: 572c4d862f
Fixes: Coverity CID 1457457
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Message-Id: <20210607223812.110596-1-richard.henderson@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

fpu/softfloat.c

@@ -4818,7 +4818,7 @@ float32 float32_exp2(float32 a, float_status *status)
 
     float_raise(float_flag_inexact, status);
 
-    float64_unpack_canonical(&xnp, float64_ln2, status);
+    float64_unpack_canonical(&tp, float64_ln2, status);
     xp = *parts_mul(&xp, &tp, status);
     xnp = xp;