bdrv_img_create() use proper errno return values

Kevin suggested to have bdrv_img_create() return proper -errno values
on error.
Signed-off-by: NJes Sorensen <Jes.Sorensen@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

block.c

@@ -2773,14 +2773,14 @@ int bdrv_img_create(const char *filename, const char *fmt,
     drv = bdrv_find_format(fmt);
     if (!drv) {
         error_report("Unknown file format '%s'", fmt);
-        ret = -1;
+        ret = -EINVAL;
         goto out;
     }
 
     proto_drv = bdrv_find_protocol(filename);
     if (!proto_drv) {
         error_report("Unknown protocol '%s'", filename);
-        ret = -1;
+        ret = -EINVAL;
         goto out;
     }
 
@@ -2799,7 +2799,7 @@ int bdrv_img_create(const char *filename, const char *fmt,
         param = parse_option_parameters(options, create_options, param);
         if (param == NULL) {
             error_report("Invalid options for file format '%s'.", fmt);
-            ret = -1;
+            ret = -EINVAL;
             goto out;
         }
     }
@@ -2809,7 +2809,7 @@ int bdrv_img_create(const char *filename, const char *fmt,
                                  base_filename)) {
             error_report("Backing file not supported for file format '%s'",
                          fmt);
-            ret = -1;
+            ret = -EINVAL;
             goto out;
         }
     }
@@ -2818,7 +2818,7 @@ int bdrv_img_create(const char *filename, const char *fmt,
         if (set_option_parameter(param, BLOCK_OPT_BACKING_FMT, base_fmt)) {
             error_report("Backing file format not supported for file "
                          "format '%s'", fmt);
-            ret = -1;
+            ret = -EINVAL;
             goto out;
         }
     }
@@ -2828,7 +2828,7 @@ int bdrv_img_create(const char *filename, const char *fmt,
         if (!strcmp(filename, backing_file->value.s)) {
             error_report("Error: Trying to create an image with the "
                          "same filename as the backing file");
-            ret = -1;
+            ret = -EINVAL;
             goto out;
         }
     }
@@ -2838,7 +2838,7 @@ int bdrv_img_create(const char *filename, const char *fmt,
         if (!bdrv_find_format(backing_fmt->value.s)) {
             error_report("Unknown backing file format '%s'",
                          backing_fmt->value.s);
-            ret = -1;
+            ret = -EINVAL;
             goto out;
         }
     }
@@ -2860,7 +2860,6 @@ int bdrv_img_create(const char *filename, const char *fmt,
             ret = bdrv_open(bs, backing_file->value.s, flags, drv);
             if (ret < 0) {
                 error_report("Could not open '%s'", filename);
-                ret = -1;
                 goto out;
             }
             bdrv_get_geometry(bs, &size);
@@ -2870,7 +2869,7 @@ int bdrv_img_create(const char *filename, const char *fmt,
             set_option_parameter(param, BLOCK_OPT_SIZE, buf);
         } else {
             error_report("Image creation needs a size parameter");
-            ret = -1;
+            ret = -EINVAL;
             goto out;
         }
     }
@@ -2901,8 +2900,6 @@ out:
     if (bs) {
         bdrv_delete(bs);
     }
-    if (ret) {
-        return 1;
-    }
-    return 0;
+
+    return ret;
 }