x86/mm: Clean up the printk()s in show_fault_oops()

- Remove 'nx_warning' and 'smep_warning', which are just pointless obfuscation.
- Also convert to pr_crit().

Suggested-by: Joe Perches <joe@perches.com>
Signed-off-by: Dmitry Vyukov <dvyukov@google.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20180627090715.28076-1-dvyukov@gmail.com


Signed-off-by: Ingo Molnar <mingo@kernel.org>