cmd: bootefi: Don't show usage help if EFI binary fails.

If an EFI binary returns an error code EFI_INVALID_PARAMETER, we show the
usage help for the bootefi command:

    Shell> exit 0x8000000000000002
    ## Application failed, r = 2
    bootefi - Boots an EFI payload from memory

    Usage:
    bootefi <image address>[:<image size>] [<fdt address>]
      - boot EFI payload
    bootefi bootmgr [fdt address]
      - load and boot EFI payload based on BootOrder/BootXXXX variables.

        If specified, the device tree located at <fdt address> gets
        exposed as EFI configuration table.

This makes no sense.

Fixes: 296faf4f7ef1 ("cmd: bootefi: re-organize do_bootefi()")
Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
Reviewed-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
diff --git a/cmd/bootefi.c b/cmd/bootefi.c
index 9cf9027..b509440 100644
--- a/cmd/bootefi.c
+++ b/cmd/bootefi.c
@@ -154,9 +154,7 @@
 	    !strcmp(argv[1], "bootmgr")) {
 		ret = efi_bootmgr_run(fdt);
 
-		if (ret == EFI_INVALID_PARAMETER)
-			return CMD_RET_USAGE;
-		else if (ret)
+		if (ret != EFI_SUCCESS)
 			return CMD_RET_FAILURE;
 
 		return CMD_RET_SUCCESS;
@@ -218,9 +216,7 @@
 
 	ret = efi_binary_run(image_buf, size, fdt);
 
-	if (ret == EFI_INVALID_PARAMETER)
-		return CMD_RET_USAGE;
-	else if (ret)
+	if (ret != EFI_SUCCESS)
 		return CMD_RET_FAILURE;
 
 	return CMD_RET_SUCCESS;