stdio_pclose: return -errno on error (v3)

This is what qemu_fclose() expects.

Changes v1 -> v2:
 - On success, keep returning pclose() return value, instead of always 0.

Changes v2 -> v3:
 - Add braces on if statements to match coding style

Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>

savevm.c

@@ -235,6 +235,9 @@ static int stdio_pclose(void *opaque)
     QEMUFileStdio *s = opaque;
     int ret;
     ret = pclose(s->stdio_file);
+    if (ret == -1) {
+        ret = -errno;
+    }
     g_free(s);
     return ret;
 }