mtd: mtdconcat: prevent a read from eraseregions[-1]
mtd: mtdconcat: prevent a read from eraseregions[-1]

If the erase region was found in the first iteration we read from
eraseregions[-1]

Signed-off-by: Roel Kluin <aa9c6213291cec1ff07688554fb7b904b9ffe4e3@gmail.com>
Signed-off-by: Andrew Morton <5c1e68b099950c134891f0b6e179498a8ebe9cf9@linux-foundation.org>
Signed-off-by: David Woodhouse <b460d66aaf00c296a3db1c1d9eeafc081d5f7d70@intel.com>

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