powerpc/oprofile: fix potential buffer overrun in op_model_cell.c

Fix potential initial_lfsr buffer overrun.
Writing past the end of the buffer could happen when index == ENTRIES

Signed-off-by: Denis Kirjanov <dkirjanov@kernel.org>
Cc: stable@kernel.org
Signed-off-by: Robert Richter <robert.richter@amd.com>
diff --git a/arch/powerpc/oprofile/op_model_cell.c b/arch/powerpc/oprofile/op_model_cell.c
index 2c9e522..7fd90d0 100644
--- a/arch/powerpc/oprofile/op_model_cell.c
+++ b/arch/powerpc/oprofile/op_model_cell.c
@@ -1077,7 +1077,7 @@
 		index = ENTRIES-1;
 
 	/* make sure index is valid */
-	if ((index > ENTRIES) || (index < 0))
+	if ((index >= ENTRIES) || (index < 0))
 		index = ENTRIES-1;
 
 	return initial_lfsr[index];