error: Remove NULL checks on error_propagate() calls

Patch created mechanically by rerunning:

  $  spatch --sp-file scripts/coccinelle/error_propagate_null.cocci \
            --macro-file scripts/cocci-macro-file.h \
            --dir . --in-place

Whitespace tidied up manually.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20181213173113.11211-1-armbru@redhat.com>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
diff --git a/blockdev.c b/blockdev.c
index e6c8349..a6f71f9 100644
--- a/blockdev.c
+++ b/blockdev.c
@@ -992,9 +992,7 @@
     blk = blockdev_init(filename, bs_opts, &local_err);
     bs_opts = NULL;
     if (!blk) {
-        if (local_err) {
-            error_propagate(errp, local_err);
-        }
+        error_propagate(errp, local_err);
         goto fail;
     } else {
         assert(!local_err);