UPSTREAM: random: Add and use pr_fmt()

Prefix all printk/pr_<level> messages with "random: " to make the
logging a bit more consistent.

Miscellanea:

o Convert a printks to pr_notice
o Whitespace to align to open parentheses
o Remove embedded "random: " from pr_* as pr_fmt adds it

Signed-off-by: Yangtao Li <tiny.windzz@gmail.com>
Link: https://lore.kernel.org/r/20190607182517.28266-3-tiny.windzz@gmail.com


Signed-off-by: Theodore Ts'o <tytso@mit.edu>
(cherry picked from commit 12cd53aff5ea0359b1dac91fcd9ddc7b9e646588)
Signed-off-by: Mark Salyzyn <salyzyn@google.com>
Bug: 148665638
Change-Id: I64f5cc7a59f746ff265d8af21744f49dc97ea128