iscsi-target: use native hex2bin for chap_string_to_hex
iscsi-target: use native hex2bin for chap_string_to_hex

This patch converts chap_string_to_hex() to use hex2bin() instead of
the internal chap_asciihex_to_binaryhex().

(nab: Fix up minor compile breakage + typo)

Signed-off-by: Andy Shevchenko <74f0c009df510614346aa771cd21959b78cdb413@linux.intel.com>
Cc: "Nicholas A. Bellinger" <978acd1567d5598152161fdf8bf3ca568f950c9b@linux-iscsi.org>
Signed-off-by: Nicholas Bellinger <978acd1567d5598152161fdf8bf3ca568f950c9b@linux-iscsi.org>

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