Btrfs: fix return value check of extent_io_ops
Btrfs: fix return value check of extent_io_ops

This patch adds the check on the return value of extent_io_ops.

Signed-off-by: Tsutomu Itoh <bbc079c7ff821d5e36ebf4ae2f9fd3690be38a1c@jp.fujitsu.com>

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