perf: Remove myself from MAINTAINERS entry

I haven't been working on perf for a while, so remove my name
from the MAINTAINERS entry for it.

Signed-off-by: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20150528061757.GB27903@iris.ozlabs.ibm.com


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