block/vpc: fix uninitialised variable compiler warning

Since commit cfc87e00 "block/vpc.c: Handle write failures in
get_image_offset()" older versions of gcc (in this case 4.7) incorrectly
warn that "ret" can be used uninitialised in vpc_co_pwritev().

Setting ret to 0 at the start of vpc_co_pwritev() prevents the warning
in gcc 4.7 and enables compilation with -Werror to succeed.

Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-id: 1500625265-23844-1-git-send-email-mark.cave-ayland@ilande.co.uk
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

diff --git a/block/vpc.c b/block/vpc.c
index 10e6519..574879b 100644 (file)
--- a/block/vpc.c
+++ b/block/vpc.c
@@ -649,7 +649,7 @@ vpc_co_pwritev(BlockDriverState *bs, uint64_t offset, uint64_t bytes,
     int64_t image_offset;
     int64_t n_bytes;
     int64_t bytes_done = 0;
-    int ret;
+    int ret = 0;
     VHDFooter *footer =  (VHDFooter *) s->footer_buf;
     QEMUIOVector local_qiov;