Small improvement to the power of 2 loop

[manishjain85]

interview/src/com/interview/bits/NextPowerOf2.java

Line 15 in 94be5de

while((num & (num-1)) > 0){

This code can be improved by following the FenwayTree logic -

while ( num & (num-1) > 0) { 
   num = num + (num & -num)
}
return num