Fix BubbleSort.c and factorial.c

[ashwek]

Description

Sorting/Bubble Sort/C/BubbleSort.c (issue #396) removed the scanf("%d",&n); line

Maths/Factorial/C/factorial.c (issue #397) declared variable n before using it. called the function factorial

Related Issue

Fixing issue #396 and #397

Types of changes

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• [x] Bug fix (change which fixes an issue with the algorithm)

• [ ] New Algorithm (non-breaking change which adds functionality)

• [ ] Documentation

Checklist:

Go over all the following points, and put an x in all the boxes that apply.

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• [x] My code follows the code style of this project.

• [ ] My change requires a change to the documentation.

• [ ] I have updated the documentation accordingly.

• [x] I have read the CONTRIBUTING document.