s390/perf,oprofile: Share sampling facility

Introduce reserve/release functions to share the sampling facility
between perf and oprofile.
Also improve error handling for the sampling facility support in perf.

Signed-off-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

diff --cc arch/s390/include/asm/perf_event.h
Simple merge

diff --cc arch/s390/kernel/perf_cpum_sf.c
Simple merge

diff --cc arch/s390/kernel/perf_event.c
Simple merge

diff --cc arch/s390/oprofile/hwsampler.c
Simple merge

diff --cc arch/s390/oprofile/init.c
Simple merge