hw/ahci: fix -Werror=maybe-uninitialized false-positive

../hw/ide/ahci.c:989:58: error: ‘tbl_entry_size’ may be used uninitialized [-Werror=maybe-uninitialized]

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Manos Pitsidianakis <manos.pitsidianakis@linaro.org>

hw/ide/ahci.c

@@ -948,7 +948,6 @@ static int ahci_populate_sglist(AHCIDevice *ad, QEMUSGList *sglist,
     uint64_t sum = 0;
     int off_idx = -1;
     int64_t off_pos = -1;
-    int tbl_entry_size;
     IDEBus *bus = &ad->port;
     BusState *qbus = BUS(bus);
 
@@ -976,6 +975,8 @@ static int ahci_populate_sglist(AHCIDevice *ad, QEMUSGList *sglist,
     /* Get entries in the PRDT, init a qemu sglist accordingly */
     if (prdtl > 0) {
         AHCI_SG *tbl = (AHCI_SG *)prdt;
+        int tbl_entry_size = 0;
+
         sum = 0;
         for (i = 0; i < prdtl; i++) {
             tbl_entry_size = prdt_tbl_entry_size(&tbl[i]);