Btrfs: remove unnecessary IS_ERR in bio_readpage_error()
Btrfs: remove unnecessary IS_ERR in bio_readpage_error()

Because the value of extent_map is only a correct value or NULL,
so IS_ERR is unnecessary.

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

TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,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