Revert "x86: bootm: Fix FIT image booting on x86"

This reverts commit 13c531e52a.

The error message with FIT style image mentioned in the above commit
only happens when booting using FIT image containing bzImage kernel
and without setup node (setup.bin). The current documentation for
x86 FIT support in doc/uImage.FIT/x86-fit-boot.txt mentions that
kernel's setup.bin file is required for building x86 FIT images.
The above commit breaks FIT images generated as described in the
documentation. Revert it to allow booting with images built in the
documented way.

Signed-off-by: Anatolij Gustschin <agust@denx.de>
Reviewed-by: Stefan Roese <sr@denx.de>
Acked-by: Bin Meng <bmeng.cn@gmail.com>

arch/x86/lib/bootm.c

@@ -109,7 +109,7 @@ static int boot_prep_linux(bootm_headers_t *images)
 		}
 		is_zimage = 1;
 #if defined(CONFIG_FIT)
-	} else if (images->fit_uname_os) {
+	} else if (images->fit_uname_os && is_zimage) {
 		ret = fit_image_get_data(images->fit_hdr_os,
 				images->fit_noffset_os,
 				(const void **)&data, &len);