x86/efi-bgrt: Switch all pr_err() to pr_notice() for invalid BGRT

The promise of pretty boot splashes from firmware via BGRT was at
best only that; a promise.  The kernel diligently checks to make
sure the BGRT data firmware gives it is valid, and dutifully warns
the user when it isn't.  However, it does so via the pr_err log
level which seems unnecessary.  The user cannot do anything about
this and there really isn't an error on the part of Linux to
correct.

This lowers the log level by using pr_notice instead.  Users will
no longer have their boot process uglified by the kernel reminding
us that firmware can and often is broken when the 'quiet' kernel
parameter is specified.  Ironic, considering BGRT is supposed to
make boot pretty to begin with.

Signed-off-by: Josh Boyer <jwboyer@fedoraproject.org>
Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Môshe van der Sterre <me@moshe.nl>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-efi@vger.kernel.org
Link: http://lkml.kernel.org/r/1462303781-8686-4-git-send-email-matt@codeblueprint.co.uk


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