efi: Remove redundant null pointer checks in efi_debugfs_init()

Since the debugfs_create_dir() never returns a null pointer, checking
the return value for a null pointer is redundant, and using IS_ERR is
safe enough.
Signed-off-by: Li Zetao <lizetao1@huawei.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>

drivers/firmware/efi/efi.c

@@ -349,7 +349,7 @@ static void __init efi_debugfs_init(void)
 	int i = 0;
 
 	efi_debugfs = debugfs_create_dir("efi", NULL);
-	if (IS_ERR_OR_NULL(efi_debugfs))
+	if (IS_ERR(efi_debugfs))
 		return;
 
 	for_each_efi_memory_desc(md) {