tools: mkeficapsule: remove duplicated code

That code is mistakenly duplicated due to copy-and-paste error.
Just remove it.

Fixes: CID 348360
Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
Reviewed-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
diff --git a/tools/mkeficapsule.c b/tools/mkeficapsule.c
index f7590e4..c118335 100644
--- a/tools/mkeficapsule.c
+++ b/tools/mkeficapsule.c
@@ -212,8 +212,6 @@
 	ret = read_bin_file(ctx->key_file, &key.data, &file_size);
 	if (ret < 0)
 		return -1;
-	if (ret < 0)
-		return -1;
 	if (file_size > UINT_MAX)
 		return -1;
 	key.size = file_size;