init/do_mounts_rd.c: fix ramdisk identification for padded cramfs
init/do_mounts_rd.c: fix ramdisk identification for padded cramfs

When a cramfs ramdisk padded with 512 bytes is given to the kernel, the
current identify_ramdisk_image function fails to identify it.

Tested with a padded cramfs image on an ARM based board.

Signed-off-by: Neil Armstrong <619b324efbf5f7848de055bdc8bef4c0dd7c8ef5@neotion.com>
Cc: Namhyung Kim <5c915a589b3ddf58cebf14bec41bcc143b37ac3c@gmail.com>
Cc: Davidlohr Bueso <bfcdf3e6ca6cef45543bfbb57509c92aec9a39fb@gnu.org>
Cc: Al Viro <de609eb4d5d70b1d38ec6642adbfc33a2781f63c@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <5c1e68b099950c134891f0b6e179498a8ebe9cf9@linux-foundation.org>
Signed-off-by: Linus Torvalds <69652caca27c8b940640ad396ab71f93cacec34f@linux-foundation.org>

KristFoundation/Programs,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas