getOldStyleBlockDevice: Adjust formatting

Instead of initializing return value to zero (success) and overwriting
it on every failure just before the control jumps onto 'out' label,
let's initialize to an error value and set to zero only when we are
sure about the success. Just follow the pattern we have in the rest of
the code.
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>

src/storage/storage_backend_scsi.c

@@ -301,27 +301,25 @@ getOldStyleBlockDevice(const char *lun_path ATTRIBUTE_UNUSED,
                        char **block_device)
 {
     char *blockp = NULL;
-    int retval = 0;
+    int retval = -1;
 
     /* old-style; just parse out the sd */
-    blockp = strrchr(block_name, ':');
-    if (blockp == NULL) {
+    if (!(blockp = strrchr(block_name, ':'))) {
         /* Hm, wasn't what we were expecting; have to give up */
         virReportError(VIR_ERR_INTERNAL_ERROR,
                        _("Failed to parse block name %s"),
                        block_name);
-        retval = -1;
+        goto cleanup;
     } else {
         blockp++;
-        if (VIR_STRDUP(*block_device, blockp) < 0) {
-            retval = -1;
-            goto out;
-        }
+        if (VIR_STRDUP(*block_device, blockp) < 0)
+            goto cleanup;
 
         VIR_DEBUG("Block device is '%s'", *block_device);
     }
 
- out:
+    retval = 0;
+ cleanup:
     return retval;
 }