grain: fix clobber list

Signed-off-by: Rémi Denis-Courmont <remi@remlab.net>

modules/video_filter/grain.c

@@ -156,6 +156,7 @@ static void BlockBlendC(uint8_t *dst, size_t dst_pitch,
 #ifdef CAN_COMPILE_SSE2
 #define _STRING(x) #x
 #define STRING(x) _STRING(x)
+VLC_SSE
 static void BlockBlendSse2(uint8_t *dst, size_t dst_pitch,
                            const uint8_t *src, size_t src_pitch,
                            const int16_t *noise)
@@ -186,7 +187,7 @@ static void BlockBlendSse2(uint8_t *dst, size_t dst_pitch,
                 [src1]"r"(&src[(2*i+0) * src_pitch]),
                 [src2]"r"(&src[(2*i+1) * src_pitch]),
                 [noise]"r"(&noise[2*i * BANK_SIZE])
-            : "memory");
+            : "xmm0", "xmm1", "xmm2", "xmm3", "xmm4", "memory");
     }
 #else
 #   error "BLEND_SIZE unsupported"