skpbench: fix typo in 6P bash script

tools/skpbench/_hardware_nexus_6p.py

Index: tools/skpbench/_hardware_nexus_6p.py
diff --git a/tools/skpbench/_hardware_nexus_6p.py b/tools/skpbench/_hardware_nexus_6p.py
index 045f9a01fd79b5a4ae6a529458473d8212268662..7e9bb5545a053591aaf63da5988ba40bf4859636 100644
--- a/tools/skpbench/_hardware_nexus_6p.py
+++ b/tools/skpbench/_hardware_nexus_6p.py
@@ -106,8 +106,8 @@ class HardwareNexus6P(HardwareAndroid):
     # unlock the 3 enabled big cores.
     self._adb.shell('''\
       for N in 6 5 4; do
-        echo 633600 > /sys/devices/system/cpu/cpu4/cpufreq/scaling_min_freq
-        echo 1958400 > /sys/devices/system/cpu/cpu4/cpufreq/scaling_max_freq
+        echo 633600 > /sys/devices/system/cpu/cpu$N/cpufreq/scaling_min_freq
+        echo 1958400 > /sys/devices/system/cpu/cpu$N/cpufreq/scaling_max_freq
         echo 0 > /sys/devices/system/cpu/cpu$N/cpufreq/scaling_setspeed
         echo interactive > /sys/devices/system/cpu/cpu$N/cpufreq/scaling_governor
       done''')