Remove NULL checks for bdrv_new return value

It's an indirect call to qemu_malloc, which never returns an error.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
diff --git a/qemu-img.c b/qemu-img.c
index 0b871d8..afd9ed2 100644
--- a/qemu-img.c
+++ b/qemu-img.c
@@ -215,10 +215,7 @@
     char password[256];
 
     bs = bdrv_new("");
-    if (!bs) {
-        error_report("Not enough memory");
-        goto fail;
-    }
+
     if (fmt) {
         drv = bdrv_find_format(fmt);
         if (!drv) {