Fix failure message formatting for Positive and Negative asserts

[lambdanis]

Summary

Error messages for Positive and Negative asserts are malformed, because of an extra argument (0) passed to the formatting function. This PR fixes that.

Changes

I moved error message formatting out of compareTwoValues function to its callers. That way all messages are formatted independently and correctly.

Motivation

The following test:

func TestNegative(t *testing.T) {
    assert.Negative(t, 1)
}

fails with the following output:

--- FAIL: TestNegative (0.00s)
    assertion_compare.go:360: 
                Error Trace:    test_test.go:20
                Error:          "1" is not negative%!(EXTRA int=0)
                Test:           TestNegative
                Messages:       []

Error message is suffixed with %!(EXTRA int=0), because Negative assert uses same function as other comparison asserts, and it includes error formatting.

Same bug occurs for Positive assert.

[mitar]

I noticed this as well.

[ccoVeille]

The PR was opened ages ago by @lambdanis

@mitar says the bug is still there.

And I tested it's confirmed. https://go.dev/play/p/ywAcp8bNkV4

=== RUN   TestNegative
    prog_test.go:11: 
        	Error Trace:	/tmp/sandbox1790707837/prog_test.go:11
        	Error:      	"1" is not negative%!(EXTRA int=0)
        	Test:       	TestNegative
--- FAIL: TestNegative (0.00s)
FAIL

@lambdanis: could you rebase and fix the conflicts or maybe close this PR if you are no longer interested?

I could reopen an PR if needed.

[lambdanis]

Sure, I'll rebase it.

[ccoVeille]

@lambdanis could you ?

[lambdanis]

Rebased.