parisc: perf: Fix potential NULL pointer dereference

[ Upstream commit 74e3f6e63da6c8e8246fba1689e040bc926b4a1a ]

Fix potential NULL pointer dereference and clean up
coding style errors (code indent, trailing whitespaces).

Signed-off-by: Arvind Yadav <arvind.yadav.cs@gmail.com>
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>