Remove new line from read sysfs stats

'\n' is appended to most sysfs values in the corresponding 'show' function.
A string value read from sysfs will be accompanied by this trailing newline.
This causes the output of dumpsys suspend_control --wakelocks and
dumpsys suspend_control --suspend_stats to be messy and difficult
to read.

Test: SystemSuspendUnitTest

Change-Id: I08372a6a198d5ed58f400c029ac0efe45e05be6b
2 files changed