ANDROID: block: Use pr_info() instead of printk(KERN_INFO ...)

Switch to the modern style of printing kernel messages. Use %u instead
of %d to print unsigned integers.

The pr_fmt() format is added on top of the file to include __func__
in the pr_info() calls.

Bug: 308663717
Bug: 319125789
Change-Id: Iea0a19c8221fe1a2fcd3f26c5ffd0c3b69935eec
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
[jyescas@google.com: define pr_fmt(fmt) to include __func__ in the output]
Signed-off-by: Juan Yescas <jyescas@google.com>