efi_loader: fix an IS_ERR() vs NULL check

The efi_parse_pkcs7_header() function returns NULL on error so the check
for IS_ERR() should be changed to a NULL check.

Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
Reviewed-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
1 file changed