UBIFS: use pr_ helper instead of printk

Use 'pr_err()' instead of 'printk(KERN_ERR', etc.

Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>

diff --cc fs/ubifs/debug.c
Simple merge

diff --cc fs/ubifs/debug.h
Simple merge

diff --cc fs/ubifs/lpt_commit.c
Simple merge

diff --cc fs/ubifs/ubifs.h
Simple merge