Commit ac7b406c1a ("arm64: Use pr_* instead of printk") was a fairly
mindless s/printk/pr_*/ change driven by a complaint from checkpatch.
As is usual with such changes, this has led to some odd behaviour on
arm64:
* syslog now picks up the "pr_emerg" line from dump_backtrace, but not
the actual trace, which leads to a bunch of "kernel:Call trace:"
lines in the log
* __{pte,pmd,pgd}_error print at KERN_CRIT, as opposed to KERN_ERR
which is used by other architectures.
This patch restores the original printk behaviour for dump_backtrace
and downgrade the pgtable error macros to KERN_ERR.
Signed-off-by: Will Deacon <will.deacon@arm.com>