BACKPORT: drivers/perf: arm_pmu: fix function type mismatch

Bug: 67506682
Change-Id: I06dc3fbef96c06cbfc8619cd2d0f7aa0fa7d99d9
Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
(cherry picked from commit 0f98f46d9920a1aad7d10916eac4b83dbccabf42)
Signed-off-by: Dan Aloni <daloni@magicleap.com>
Signed-off-by: Davide Garberi <dade.garberi@gmail.com>
diff --git a/drivers/perf/arm_pmu.c b/drivers/perf/arm_pmu.c
index 9ffa228..2a6a161 100755
--- a/drivers/perf/arm_pmu.c
+++ b/drivers/perf/arm_pmu.c
@@ -989,7 +989,7 @@
 			 const struct pmu_probe_info *probe_table)
 {
 	const struct of_device_id *of_id;
-	const int (*init_fn)(struct arm_pmu *);
+	int (*init_fn)(struct arm_pmu *);
 	struct device_node *node = pdev->dev.of_node;
 	struct arm_pmu *pmu;
 	int ret = -ENODEV;