x86/float_dsp: zero extend offset from ff_scalarproduct_float_sse

Reviewed-by: Christophe Gisquet <christophe.gisquet@gmail.com>
Signed-off-by: James Almer <jamrial@gmail.com>

libavutil/x86/float_dsp.asm

@@ -332,10 +332,10 @@ VECTOR_FMUL_REVERSE
 ; float scalarproduct_float_sse(const float *v1, const float *v2, int len)
 INIT_XMM sse
 cglobal scalarproduct_float, 3,3,2, v1, v2, offset
+    shl   offsetd, 2
+    add       v1q, offsetq
+    add       v2q, offsetq
     neg   offsetq
-    shl   offsetq, 2
-    sub       v1q, offsetq
-    sub       v2q, offsetq
     xorps    xmm0, xmm0
 .loop:
     movaps   xmm1, [v1q+offsetq]