Fixed scientific convention issue in image size

[Affan-7]

This fixes #3091

In this code HumanSizeWithPrecision() method is used.

This method takes two parameters size and precision.

- Here is what I did:

I tried to reproduce the bug with this code.

package main

import (
	"fmt"

	"github.com/docker/go-units"
)

func main() {
	fmt.Println(units.HumanSizeWithPrecision(float64(999900000), 3))
}

And this resulted in 1e+03MB being output.

So I changed precision from 3 to 4 like the following.

package main

import (
	"fmt"

	"github.com/docker/go-units"
)

func main() {
	fmt.Println(units.HumanSizeWithPrecision(float64(999900000), 4))
}

And this gave me 999.9MB output.

In conclusion, this unexpected scientific convention results when we use precision 3.

In go-unit library the HumanSize() method uses HumanSizeWithPrecision(size, 4) method under the hood, So I used HumanSize() instead of using HumanSizeWithPrecision().

- Description for the changelog

Replaced HumanSizeWithPrecision() with HumanSize().

- A picture of a cute animal (not mandatory but encouraged)

[codecov-commenter]

Codecov Report

Merging #4459 (1d981e2) into master (8837d11) will not change coverage.
The diff coverage is 100.00%.

Additional details and impacted files

@@           Coverage Diff           @@
##           master    #4459   +/-   ##
=======================================
  Coverage   59.39%   59.39%           
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  Files         288      288           
  Lines       24782    24782           
=======================================
  Hits        14720    14720           
  Misses       9175     9175           
  Partials      887      887           

[neersighted]

Looks like this passes the existing tests, which is good. Can you please add a regression test (using your sample values from the PR body) to demonstrate the correctness of the fix/ensure we don't reintroduce it later?