Btrfs: don't change file extent's ram_bytes in btrfs_drop_extents
Btrfs: don't change file extent's ram_bytes in btrfs_drop_extents

btrfs_drop_extents doesn't change file extent's ram_bytes
in the case of booked extent. To be consistent, we should
also not change ram_bytes when truncating existing extent.

Signed-off-by: Yan Zheng <f59400d51e9f1681db20659c0770e89f5d557a2e@oracle.com>


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