perf utils: Fix spelling mistake: "Invalud" -> "Invalid"

perf utils: Fix spelling mistake: "Invalud" -> "Invalid"

Trivial fix to spelling mistake in pr_debug message.

Signed-off-by: Colin King <colin.king@canonical.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Krister Johansen <kjlx@templeofstupid.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: kernel-janitors@vger.kernel.org
Link: http://lkml.kernel.org/r/20170330095440.19444-1-colin.king@canonical.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>