Correct errors

Correct errors

Add the logic of null check to a variable.
Change the inner class to the static inner class.
Release the resources.
Add explicit type casting.
Change the final variable to the final static variable.
If the string concatenation occurs in the loop, change it to use the StringBuffer.
Change the string object generated with no argument to the empty string object.
When you read/write operation in file, explicitly set to use a "UTF-8" encoding.
Remove build dependancy.
Modify error message for the oprofile's path.

Change-Id: I8b211c9b426a5ae7ed03a6f8a9e0668285c8621f
Signed-off-by: seokgil.kang <seokgil.kang@samsung.com>