fix compiler warning when enabling LTC_GCM_TABLES_SSE2

src/encauth/gcm/gcm_mult_h.c

@@ -25,7 +25,7 @@ void gcm_mult_h(gcm_state *gcm, unsigned char *I)
 {
    unsigned char T[16];
 #ifdef LTC_GCM_TABLES
-   int x, y;
+   int x;
 #ifdef LTC_GCM_TABLES_SSE2
    asm("movdqa (%0),%%xmm0"::"r"(&gcm->PC[0][I[0]][0]));
    for (x = 1; x < 16; x++) {
@@ -33,6 +33,7 @@ void gcm_mult_h(gcm_state *gcm, unsigned char *I)
    }
    asm("movdqa %%xmm0,(%0)"::"r"(&T));
 #else
+   int y;
    XMEMCPY(T, &gcm->PC[0][I[0]][0], 16);
    for (x = 1; x < 16; x++) {
 #ifdef LTC_FAST